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Showing papers in "ACS Sustainable Chemistry & Engineering in 2018"


Journal ArticleDOI
TL;DR: In this paper, the current status of spent lithium-ion battery recycling is summarized in light of the whole recycling process, especially focusing on the hydrometallurgy, which is used to extract metals or separate impurities from a specific waste stream so that the recycled materials or compounds can be further prepared by incorporating principles of materials engineering.
Abstract: Recycling of spent lithium-ion batteries (LIBs) has attracted significant attention in recent years due to the increasing demand for corresponding critical metals/materials and growing pressure on the environmental impact of solid waste disposal. A range of investigations have been carried out for recycling spent LIBs to obtain either battery materials or individual compounds. For the effective recovery of materials to be enhanced, physical pretreatment is usually applied to obtain different streams of waste materials ensuring efficient separation for further processing. Subsequently, a metallurgical process is used to extract metals or separate impurities from a specific waste stream so that the recycled materials or compounds can be further prepared by incorporating principles of materials engineering. In this review, the current status of spent LIB recycling is summarized in light of the whole recycling process, especially focusing on the hydrometallurgy. In addition to understanding different hydromet...

634 citations


Journal ArticleDOI
TL;DR: The first green chemistry metrics, the E factor (kgs waste/kg product) and atom economy (mol wt of product/sum of mol wts of starting materials), were introduced in the early 1990s and were actually green chemistry avant la lettre as mentioned in this paper.
Abstract: The first green chemistry metrics—the E factor (kgs waste/kg product) and atom economy (mol wt of product/sum of mol wts of starting materials)—were introduced in the early 1990s and were actually green chemistry avant la lettre. In the last two decades, these two metrics have been adopted worldwide by both academia and industry. The E factor has been refined to distinguish between simple and complete E factors, for example, and to define the system boundaries. Other mass-based metrics such as process mass intensity (PMI) and reaction mass efficiency (RME) have been proposed. However, mass-based metrics need to be augmented by metrics which measure the environmental impact of waste, such as life cycle assessment (LCA), and metrics for assessing the economic viability of products and processes. The application of such metrics in measuring the sustainability of processes for the manufacture of pharmaceuticals and other fine chemicals is discussed in detail. Mass-based metrics alone are not sufficient to mea...

543 citations


Journal ArticleDOI
TL;DR: In this article, a 2D/2D g-C3N4/MnO2 heterostructured photocatalyst was synthesized via in situ growth of MnO2 nanosheets on the surface of G-C 3N4 nanolayers using a wet-chemical method.
Abstract: Constructing two-dimensional (2D) composites using layered materials is considered to be an effective approach to achieve high-efficiency photocatalysts. Herein, a 2D/2D g-C3N4/MnO2 heterostructured photocatalyst was synthesized via in situ growth of MnO2 nanosheets on the surface of g-C3N4 nanolayers using a wet-chemical method. The hybrid nanomaterial was characterized by a range of techniques to study its micromorphology, structure, chemical composition/states, and so on. The g-C3N4/MnO2 nanocomposite exhibited greatly improved photocatalytic activities for dye degradation and phenol removal in comparison to the single g-C3N4 or MnO2 component. On the basis of the electron paramagnetic resonance spectra, X-ray photoelectron spectra, and the Mott–Schottky measurements, we consider that a Z-scheme heterojunction was generated between the g-C3N4 nanosheets and MnO2 nanosheets, wherein the photoinduced electrons in MnO2 combined with the holes in g-C3N4, leading to enhanced charge carrier extraction and ut...

490 citations


Journal ArticleDOI
TL;DR: A comprehensive review of the literature about different feedstock lignin and versatile Lignin derivatives used as heavy metal ion adsorbents is provided in this article, where the adsorption capability improvement mechanism and comparison with commercial resins are also discussed.
Abstract: Water pollution by heavy metal ions is currently of great concern due to their high toxicity and carcinogenicity. In recent years, great efforts have been devoted to the search for new cost-effective adsorbents derived from biomass. Lignin is a natural amorphous polymer that has great potential for use as a building block in the production of biorenewable materials. Due to its unique polyphenol structure, physicochemical properties, and abundance, a wide variety of sorbents, particularly heavy metal ion sorbents, can be potentially obtained from lignin. This paper provides a comprehensive review of the literature about different feedstock lignin and versatile lignin derivatives used as heavy metal ion adsorbents. The adsorption capability improvement mechanism of the lignin derivatives and the comparison with commercial resins are also discussed. Therefore, this review aims to discuss the different modification categories that have been reported for the conversion of lignins into advanced heavy metal ion ...

354 citations


Journal ArticleDOI
TL;DR: The amount of spent lithium-ion batteries has grown dramatically in recent years, and the development of a recycling process for spent lithium ion batteries is necessary and urgent from the view of.
Abstract: The amount of spent lithium-ion batteries has grown dramatically in recent years, and the development of a recycling process for spent lithium-ion batteries is necessary and urgent from the viewpoi...

332 citations


Journal ArticleDOI
TL;DR: In this paper, hollow cobalt sulfide (CoS) is used as a cocatalyst to realize highly efficient photocatalytic hydrogen (H2) production in the field of solar energy conversion.
Abstract: Seeking for a suitable cocatalyst to realize highly efficient photocatalytic hydrogen (H2) production is a great challenge in the field of solar energy conversion. Herein, hollow cobalt sulfide (Co...

322 citations


Journal ArticleDOI
TL;DR: In this article, the performance of cellulose nanomaterials (CNMs) acting as a barrier against moisture and oxygen permeation in CNM films, CNM-coated polymers and papers, and CNM reinforced polymer composites is analyzed.
Abstract: Applications of cellulose nanomaterials (CNMs) have attracted increasing attention in recent years. One conceivable path lies in their commercial applications for packaging, in which their barrier properties will play an important role in determining their competiveness with conventional materials. This review critically analyzes the performance of CNMs acting as a barrier against moisture and oxygen permeation in CNM films, CNM-coated polymers and papers, and CNM-reinforced polymer composites, gives some insights into remaining challenges, and brings an overall perspective of compositing CNMs with other materials to achieve balanced properties adequate for barrier packaging. In general, CNMs are a poor moisture barrier but excellent oxygen barrier in the dry state and are still good below 65% relative humidity. The addition of CNMs can improve the oxygen barrier of the resulting polymer composites; however, neat CNM coatings and films can afford better oxygen barrier properties than dispersed CNMs in coa...

312 citations


Journal ArticleDOI
TL;DR: In this paper, the importance of agriculture waste and pretreatments, methods involved in the production of nanocellulose, and the properties of NC prepared from crop and industrial waste.
Abstract: Nano-sized cellulose materials has recently become topical in the sphere of sustainable materials. The two key groups of nanocelluloses (NCs) are (1) nanofibrillated cellulose (NFC) and (2) cellulose nanocrystals (CNC). They are often considered as second-generation renewable resources, which also serve as better replacements for petroleum-based products. More attention has been given to these materials because of their low density and high mechanical, renewable, and biodegradable properties. There are many works in the literature on the isolation of NFC and CNC from different sources like hard/soft wood and agriculture biomass. However, this is a comprehensive review dedicated to the properties of NFC and CNC extracted only from agriculture and industrial waste using mechanical, chemical, and enzymatic methods. This article explores in detail the importance of agriculture waste and pretreatments, methods involved in the production of nanocellulose, and the properties of NC prepared from crop and industri...

306 citations


Journal ArticleDOI
TL;DR: In this article, the authors proposed a 3D porous Fe3O4/C composite flowers with an average size of 4-6 μm and an optimal reflection loss (RL) value of −54.6 dB at 5.7 GHz at a thin thickness of 4.27 mm.
Abstract: Magnetite (Fe3O4)/carbon (C) composite flowers with an average size of 4–6 μm were prepared through a facile route including a solvothermal approach and a carbon reduction process. The resultant Fe3O4/C composites are porous and exhibit a three-dimensional (3D) flower-like morphology with the core–shell Fe3O4@C nanoparticles hybridized by amorphous carbon sheets. The epoxy resin composites containing 50 wt % 3D porous Fe3O4/C composite flowers display an optimal reflection loss (RL) value of −54.6 dB at 5.7 GHz at a thin thickness of 4.27 mm and the effective bandwidth with RL < −10 dB reaches 6.0 GHz at a thickness of 2.1 mm. These enhanced EM wave absorption performances are attributed to the synergistic effects of Fe3O4 and carbon as well as the structural advantages, e.g., three-dimensional structure with large surface area, porous and core–shell structures of Fe3O4/C flowers. These results suggest the 3D porous Fe3O4/C composite flowers designed here can serve as ideal candidates for high-performance...

306 citations


Journal ArticleDOI
TL;DR: In this paper, the authors discuss many of these approaches, and highlight efforts to sustainably produce recyclable cross-linked polymers, and present their thoughts on future challenges that must be overcome to enable widespread, viable, and more sustainable and practical implementation of these materials, including the sustainable sourcing of f...
Abstract: Cross-linked polymers are ubiquitous in daily life, finding applications as tires, insulation, adhesives, automotive parts, and countless other products. The covalent cross-links in these materials render them mechanically robust, chemically resistant, and thermally stable, but they also prevent recycling of these materials into similar-value goods. Furthermore, cross-linked polymers are typically produced from petroleum-based feedstocks, and their hydrocarbon backbones render them nondegradable, making them unsustainable in the long term. In recent years, much effort has focused on the development of recycling strategies for cross-linked polymeric materials. In the following Perspective, we discuss many of these approaches, and highlight efforts to sustainably produce recyclable cross-linked polymers. We present our thoughts on future challenges that must be overcome to enable widespread, viable, and more sustainable and practical implementation of these materials, including the sustainable sourcing of f...

290 citations


Journal ArticleDOI
TL;DR: Li et al. as mentioned in this paper synthesized sandwiched nanocomposites made of Fe3O4 nanoparticles, poly(allylamine) hydrochloride molecules, and carboxylate graphene oxide sheets using a layer-by-layer self-assembly method.
Abstract: Two-dimensional (2D) carbon nanomaterials generally display some limitations in adsorption applications due to easy agglomeration. To solve this problem, as-synthesized sandwiched nanocomposites made of Fe3O4 nanoparticles, poly(allylamine) hydrochloride molecules, and carboxylate graphene oxide sheets were prepared using a layer-by-layer (LbL) self-assembly method. The successfully synthesized sandwiched structures in the present nanocomposites have outstanding organic dye adsorption performance, stability, and recycling. The agglomeration of carboxylate graphene oxide was reduced with increased specific surface area because the Fe3O4 nanoparticles play important roles in interpenetrating and supporting graphene oxide sheets layers. In comparison with other kinds of composite adsorbents, the preparation process of the present new sandwiched composite materials is facile to operate and regulate, which demonstrates potential large-scale applications in wastewater treatment and dye removal.

Journal ArticleDOI
TL;DR: In this paper, the Co-CuO nanoarray on copper foam requires a current densities of 50 and 100 mA cm−2 at overpotentials of only 299 and 330 mV, respectively.
Abstract: It is highly desired to enhance the catalytic activity of oxygen evolution reaction (OER) electrocatalysts made of earth-abundant elements In this Letter, we report that the OER activity of a CuO nanoarray can be largely enhanced by Co doping In 10 M KOH, the Co-CuO nanoarray on copper foam requires a current densities of 50 and 100 mA cm–2 at overpotentials of only 299 and 330 mV, respectively It also shows superior long-term durability over 15 h with a turnover frequency of 0056 mol O2 s–1 at an overpotential of 300 mV

Journal ArticleDOI
TL;DR: In this article, the authors focus on the utilization of metal-organic framework-derived (MOF-derived) materials as effective solid catalysts for the valorization of biomass into platform chemicals.
Abstract: Over the past decade, the development in the valorization of biomass technologies keeps increasing because the biomass utilization for manufacturing fine chemicals and fuels has diverse advantages over fossil feedstock. The review focuses on the utilization of metal–organic framework-derived (MOF-derived) materials as effective solid catalysts for the valorization of biomass into platform chemicals. MOFs compose of abundant organic ligands and metal cluster, and additional functional groups, could be modified on ligands (or metal clusters) serving as active sites. On the other hand, MOFs could also be converted into porous carbons or metal oxide composites by calcination at nitrogen or air, respectively, for catalytic reactions. These MOF-derived catalysts feature advantages like high specific surface area, porosity, and active sites from mother MOFs. More importantly, stronger interactions between guests (i.e., metal or alloy NPs) and hosts (i.e., MOF-derived carbons or metal oxides) make these catalysts...

Journal ArticleDOI
TL;DR: In this paper, the pyrolysis temperature plays an important role in determining the electromagnetic properties of these hollow Co/C microspheres, where high pyrolysis temperature will increase relative complex permittivity and decrease relative complex permeability.
Abstract: Rational construction of a profitable microstructure in carbon-based electromagnetic composites is becoming a promising strategy to reinforce their microwave absorption performance. Herein, the microstructure design is innovatively coupled with a metal–organic frameworks (MOFs)-derived method to produce hollow Co/C microspheres (Co/C-HS). The resultant composites combine the advantages of hollow microstructures and good chemical homogeneity. It is found that the pyrolysis temperature plays an important role in determining the electromagnetic properties of these hollow Co/C microspheres, where high pyrolysis temperature will increase relative complex permittivity and decrease relative complex permeability. When the pyrolysis temperature is 600 °C, the sample (Co/C-HS-600) will show improved impedance matching and good attenuation ability, and thus an excellent microwave absorption performance with strong reflection loss (−66.5 dB at 17.6 GHz) and wide response bandwidth (over −10 dB, 3.7–18.0 GHz) can be a...

Journal ArticleDOI
TL;DR: A detailed review of the literature (both patents and publications) so far on hydesal is critically evaluated, and prospects and directions to commercialize the HyDesal process are presented as mentioned in this paper.
Abstract: Water resource management impacts almost all aspects of the economy, in particular health, food production and security, domestic water supply and sanitation, energy, industry and environmental sustainability. For the last several decades, seawater has become an important source of fresh water as it is one of the most abundant resources on earth. Desalination is the process of removal of salts from seawater and is postulated to be a core technology in alleviating this problem. Clathrate hydrate based desalination (HyDesal) is a potential technology for seawater desalination. Salts are excluded from hydrate formation, thereby resulting in solid hydrate and concentrated brine. After separation from brine, the solid hydrate crystals upon dissociation produce pure water. In this work, a detailed review of the literature (both patents and publications) so far on HyDesal is critically evaluated, and prospects and directions to commercialize the HyDesal process are presented. Further, innovation by coupling LNG ...

Journal ArticleDOI
TL;DR: In this article, a lead-free NaNbO3-based lead free ceramic capacitance with fast charge-discharge performance and excellent energy storage characteristics has been proposed.
Abstract: Recently, ceramic capacitors with fast charge–discharge performance and excellent energy storage characteristics have received considerable attention. Novel NaNbO3-based lead-free ceramics (0.80NaN...

Journal ArticleDOI
TL;DR: In this paper, a Bi surface plasmon resonance (SPR)-promoted Z-scheme Bi2MoO6 nanosheet/CdS-diethylenetriamine (Bi-Bi 2MoO 6/Cds-DETA) composites were synthesized via an in situ solvothermal method.
Abstract: Recently, CdS has been intensively investigated for its excellent photocatalytic hydrogen (H2) evolution property. However, the poor stability and serious photocorrosion severely influence its potential for practical application. In this work, we successfully synthesized Bi surface plasmon resonance (SPR)-promoted Z-scheme Bi2MoO6 nanosheet/CdS-diethylenetriamine (Bi–Bi2MoO6/CdS-DETA) composites via an in situ solvothermal method. Crystalline structure, morphology, electrochemical properties, along with the photocatalytic H2 evolution activity and stability, have been systematically investigated. The as-prepared Bi–Bi2MoO6/CdS-DETA composites with optimized structure exhibited advanced photocatalytic H2 evolution activity (reach to 7.37 mmol h–1 g–1) and high stability. Largely exposed active sites, effective Z-scheme charge separation and Bi metal SPR effect of the two-dimension (2D) heterostructure is contributed to improve H2 generation performance of Bi–Bi2MoO6/CdS-DETA composites. This work provides ...

Journal ArticleDOI
TL;DR: In this paper, a novel visible-light-driven photocatalyst AgI/Bismarck was proposed, which can utilize more sunlight for reactions than conventional photocatalysts.
Abstract: Visible-light-driven photocatalysts attract great interest because they can utilize more sunlight for reactions than conventional photocatalysts. A novel visible-light-driven photocatalyst AgI/Bism...

Journal ArticleDOI
TL;DR: In this paper, a novel strategy of utilizing loofah sponge as 3D hierarchical porous carbon precursors and ferric nitrate as magnetic precursor to prepare magnetic hierarchical porous composites, which exhibit tunable high-performance microwave absorption (MA) was proposed.
Abstract: Recently, three-dimensional (3D) porous carbon materials derived from biomass have been gaining interest as promising microwave absorbers due to their low cost, vast availability, and sustainability of biomasses. Herein, a novel strategy of utilizing loofah sponge as 3D hierarchical porous carbon precursors and ferric nitrate as magnetic precursor to prepare magnetic hierarchical porous carbon composites, which exhibit tunable high-performance microwave absorption (MA). During the carbonization process, the 3D-bundled microtube structure of loofah sponge changes into interconnected networks with hierarchical porous structures, and the precursor ferric nitrate converts into magnetic Fe3O4@Fe nanoparticles. As expected, the as-obtained loofah sponge-derived 3D porous carbon/Fe3O4@Fe composites treated at 600 °C exhibit outstanding MA performance. It displays the minimum reflection loss (RL) of −49.6 dB with a thickness of 2 mm, and the effective absorption bandwidth (RL≤ 10 -dB) can reach 5.0 GHz (from 13 t...

Journal ArticleDOI
TL;DR: In this paper, the robust copper phosphide (Cu3P) nanoparticles may serve as a cocatalyst and a p-type semiconductor at low (1.5 wt %) and high loading contents, respectively.
Abstract: The rational design of sustainable noble-metal-free heterojunctions remains a key challenge for highly efficient and durable photocatalytic H2 production. In this study, it was revealed that the robust copper phosphide (Cu3P) nanoparticles may serve as a cocatalyst and a p-type semiconductor at low (1.5 wt %) and high (10 wt %) loading contents, respectively. Both Cu3P cocatalyst and semiconductor could evidently boost visible-light-driven photocatalytic H2 production over graphitic carbon nitride (g-C3N4) nanosheets. Comparably speaking, the heterojunction effects between p-type Cu3P and n-type g-C3N4 are speculated to play a more prominent role in dramatically boosting photocatalytic H2 production than the electron-sink roles of surface Cu3P cocatalysts. Impressively, among all the as-fabricated photocatalysts, high quality 10 wt % g-C3N4–Cu3P could achieve the highest photocatalytic H2-production rate of 159.41 μmol g–1 h–1, which is approximately 1014 times higher than that of pristine g-C3N4. In cycl...

Journal ArticleDOI
TL;DR: In this article, three DESs were prepared by exclusively combining fatty acids, namely octanoic acid (C8), non-anoic acids (C9), decanoic acyclic acid(C10), and dodecanoic al- acids(C12), which can simultaneously act as hydrogen bond donors and acceptors.
Abstract: Inspired by the use of fatty acids in development of low temperature latent heat storage materials, novel low viscous and hydrophobic deep eutectic solvents (DESs) based exclusively on fatty acids are herein proposed as sustainable solvents. Three DESs were prepared by exclusively combining fatty acids, namely octanoic acid (C8), nonanoic acid (C9), decanoic acid (C10), and dodecanoic acid (C12), which can simultaneously act as hydrogen bond donors and acceptors. The obtained fatty acid-based DESs were analyzed in order to check their structures, purities, and proportions. Water stability was also carefully evaluated through 1H NMR. Fatty-acid DESs melting point diagrams were determined by visual observation. Good agreement was obtained between the experimental eutectic point and that predicted by considering an ideal system of two individually melting compounds. Important solvent thermophysical properties, such as density and viscosity of the dried and water-saturated DESs, were measured. Finally, the re...

Journal ArticleDOI
TL;DR: In this article, the effect of pore size on electrocatalytic performance of carbon-based catalysts for hydrogen peroxide (H2O2) has been explored.
Abstract: Hydrogen peroxide (H2O2), an important industrial chemical, is currently produced through an energy-intensive anthraquinone process that is limited to large-scale facilities. Small-scale decentralized electrochemical production of H2O2 via a two-electron oxygen reduction reaction (ORR) offers unique opportunities for sanitization applications and the purification of drinking water. The development of inexpensive, efficient, and selective catalysts for this reaction remains a challenge. Herein, we examine two different porous carbon-based electrocatalysts and show that they exhibit high selectivity for H2O2 under alkaline conditions. By rationally varying synthetic methods, we explore the effect of pore size on electrocatalytic performance. Furthermore, by means of density functional calculations, we point out the critical role of carbon defects. Our theory results show that the majority of defects in graphene are naturally selective for the two-electron reduction of O2 to H2O2, and we identify the types o...

Journal ArticleDOI
TL;DR: In this paper, a novel TiO2/NiS core-shell nanohybrid was fabricated where few-layer NiS nodes were used for photocatalytic water splitting to generate hydrogen.
Abstract: Photocatalytic water splitting to generate hydrogen (H2) is a sustainable approach for solving the current energy crisis. A novel TiO2/NiS core–shell nanohybrid was fabricated where few-layer NiS n...

Journal ArticleDOI
TL;DR: In this article, recent advances in the area of biomass-derived C6-furanic platform chemicals for sustainable biomass processing are analyzed focusing on chemical reactions important for development of practical applications and materials science.
Abstract: Recent advances in the area of biomass-derived C6-furanic platform chemicals for sustainable biomass processing are analyzed focusing on chemical reactions important for development of practical applications and materials science. Among the chemical processes currently being studied, tuning the amount of oxygen-containing functional groups remains the most active research direction. Production of efficient fuels requires the removal of oxygen atoms (reduction reactions), whereas utilization of biomass-derived furanic derivatives in material science points out the importance of oxidation in order to form dicarboxylic derivatives. Stimulated by this driving force, oxidation and reduction of 5-(hydroxymethyl)furfural (HMF) are nowadays massively studied. Moreover, these fundamental transformations are often used as model reactions to test new catalysts, and HMF transformations guide the development of new catalytic systems. From the viewpoint of organic synthesis, highly diverse chemical reactivity is explor...

Journal ArticleDOI
TL;DR: In this article, a superhydrophobic/superoleophilic porous polycarbonate/carboxyl-functionalized multiwalled carbon nanotubes (PC/cMWCNTs) monolith with novel hierarchical micronanostructure was facilely fabricated via a thermally impacted nonsolvent induced phase separation method.
Abstract: A superhydrophobic/superoleophilic porous polycarbonate/carboxyl-functionalized multiwalled carbon nanotubes (PC/cMWCNTs) monolith with novel hierarchical micronanostructure was facilely fabricated via a thermally impacted nonsolvent induced phase separation method. A novel porous microstructure endowed PC/cMWCNTs monolith had a high porosity of 90.1%. Based on excellent superhydrophobicity (water contact angle of 159°) and superoleophilicity (oil contact angle of 0°), this porous monolith could selectively adsorb various types of oils/organic solvents from the oil–water mixture. Additionally, the monolith exhibited outstanding oil/water separation performance including fast adsorption speed, high saturation capacity, and superior recycling ability. The equilibrium adsorption time and saturated adsorption capacity of soybean oil were 20 s and 12.62 g g–1, respectively. By simple centrifugation or evaporation, the recovered PC/cMWCNTs monolith could be reused for at least 10 cycles. Thus, porous PC/cMWCNTs...

Journal ArticleDOI
TL;DR: In this paper, the characterization of eutectic solvents composed of the terpenes thymol or l(−)-menthol and monocarboxylic acids is studied aiming the design of these solvements.
Abstract: Recently, some works claim that hydrophobic deep eutectic solvents could be prepared based on menthol and monocarboxylic acids. Despite of some promising potential applications, these systems were poorly understood, and this work addresses this issue. Here, the characterization of eutectic solvents composed of the terpenes thymol or l(−)-menthol and monocarboxylic acids is studied aiming the design of these solvents. Their solid–liquid phase diagrams were measured by differential scanning calorimetry in the whole composition range, showing that a broader composition range, and not only fixed stoichiometric proportions, can be used as solvents at low temperatures. Additionally, solvent densities and viscosities close to the eutectic compositions were measured, showing low viscosity and lower density than water. The solvatochromic parameters at the eutectic composition were also investigated aiming at better understanding their polarity. The high acidity is mainly provided by the presence of thymol in the m...

Journal ArticleDOI
TL;DR: In this article, the synergistic effect of metal-organic framework derived earth-abundant Co2P cocatalysts and the robust bio-inspired environmental phosphorylation strategy in boosting photocatalyic H2 generation over the graphitic carbon nitride (g-C3N4) nanosheets was thoroughly investigated and revealed.
Abstract: Highly active and durable earth-abundant cocatalysts and photocatalysts are under increasing demand in developing practical hydrogen-evolution reaction (HER) systems. Especially, exploiting noble-metal-free Pt-like HER cocatalysts still remains a significant challenge. In this study, the synergistic effect of metal–organic framework (MOF) derived earth-abundant Co2P cocatalysts and the robust bioinspired environmental phosphorylation strategy in boosting photocatalyic H2 generation over the graphitic carbon nitride (g-C3N4) nanosheets was thoroughly investigated and revealed. The maximum H2-evolution rate of the ternary g-C3N4-Co2P-K2HPO4 photocatalytic systems could reach 27.81 μmol h–1, which was approximately 556 times higher than that of pure g-C3N4 nanosheets. The loaded earth-abundant Co2P nanoparticles with a good electrical conductivity could not only improve visible-light absorption and decrease the recombination of the electron–hole pairs, but also mainly serve as an efficient cocatalyst to lowe...

Journal ArticleDOI
TL;DR: In this paper, the authors demonstrate that MoN nanosheets array on carbon cloth (MoN NA/CC) acts as a high-performance N2 reduction reaction (NRR) electrocatalyst toward NH3 electro synthesis in 0.1 M HCl under ambient conditions.
Abstract: Electrochemical N2 reduction reaction (NRR) under ambient conditions offers us an environmentally friendly route for artificial synthesis of NH3. However, up to now, few noble-metal-free electrocatalysts with satisfactory catalytic activities have been explored. In this Letter, we demonstrate that MoN nanosheets array on carbon cloth (MoN NA/CC) acts as a high-performance NRR electrocatalyst toward NH3 electrosynthesis in 0.1 M HCl under ambient conditions. This catalyst achieves a large NH3 yield of 3.01 × 10–10 mo1 s–1 cm–2 and a Faradaic efficiency of 1.15% at −0.3 V vs reversible hydrogen electrode with strong electrochemical durability and selectivity. Density functional theory calculations reveal that MoN NA/CC catalyzes NRR via the Mars–van Krevelen mechanism.

Journal ArticleDOI
TL;DR: In this paper, the influence of the precipitation procedures on particle size, Zeta potential, molecular weight, and thermal stability of the final obtained lignin nanoparticles was investigated.
Abstract: In this study, dissolution of pristine alkali lignin into ethylene glycol, followed by addition of different acidic conditions (HCl, H2SO4, and H3PO4 at different pH) has been considered as a simple method to prepare high yield lignin nanoparticles (LNP). Field emission scanning electron microscopy (FESEM), Zeta potential, gel permeation chromatography (GPC), and thermogravimetric analysis (TGA) have been utilized to determine the influence of the precipitation procedures on particle size, Zeta potential, molecular weight, and thermal stability of final obtained LNP. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and nuclear magnetic resonance (NMR) were also considered to investigate the influence of lignin chemical structures and composition on its antioxidative and antimicrobial behaviors. Results from DPPH (1,1-diphenyl-2-picryl-hydrazyl) activity revealed the antioxidant response of LNP aqueous solutions, whereas results from antimicrobial tests confirmed LNP ...

Journal ArticleDOI
TL;DR: In this article, the P-doped Ag nanoparticles embedded in N-Doped carbon nanoflake (P-Ag@NC) were used for effective hydrogen evolution electrocatalysis.
Abstract: Electrolytic hydrogen generation needs efficient and durable electrocatalysts for the hydrogen evolution reaction. In this Letter, for the first time, we report on the development of P-doped Ag nanoparticles embedded in N-doped carbon nanoflake (denoted as “P-Ag@NC”) for effective hydrogen evolution electrocatalysis. When tested in 0.5 M H2SO4, such P-Ag@NC demands overpotential of only 78 mV to drive a catalytic current density of 10 mA cm–2, which is 198 mV less than that of Ag@NC counterpart. Remarkably, this catalyst also shows strong long-term electrochemical durability with the preservation of its catalytic activity for at least 85 h. Density functional theory calculations suggest that P doping brings the optimization of hydrogen adsorption free energy to a more thermo-neutral value.