Catalytic reduction of nitrophenols and dyes using silver nanoparticles @ cellulose polymer paper for the resolution of waste water treatment challenges

The construction of heterojunctions provides a promising strategy to improve photocatalytic hydrogen evolution. However, how to fabricate a nanoscale TiO2/g-C3N4 heterostructure and hinder the aggregation of bulk g-C3N4 using simple methods remains a challenge. In this work, we use a simple in situ construction method to design a heterojunction model based on molecular self-assembly, which uses a small molecule matrix for self-integration, including coordination donors (AgNO3), inorganic titanium source (Ti(SO4)2) and g-C3N4 precursor (melamine). The self-assembled porous g-C3N4 nanotube can hamper carrier aggregation and it provides numerous catalytic active sites, mainly via the coordination of Ag+ ions. Meanwhile, the TiO2 NPs are easily mineralized on the nanotube template in dispersive distribution to form a heterostructure via an N-Ti bond of protonation, which contributes to shortening the interfacial carrier transport, resulting in enhanced electron-hole pairs separation. Originating from all of the above synergistic effects, the obtained Ag/TiO2/g-C3N4 heterogenous photocatalysts exhibit an enhanced H2 evolution rate with excellent sustainability 20.6-fold-over pure g-C3N4. Our report provides a feasible and simple strategy to fabricate a nanoscale heterojunction incorporating g-C3N4, and has great potential in environmental protection and water splitting.

In Situ Construction of Ag/TiO2/g-C3N4 Heterojunction Nanocomposite Based on Hierarchical Co-Assembly with Sustainable Hydrogen Evolution.

The useful functionalization and self-assembly of two-dimensional layered materials like hydrotalcite (LDH) are critical for the wide application of nanomaterials. In this work, some self-assembled...

Facile Preparation of Self-Assembled Layered Double Hydroxide-Based Composite Dye Films As New Chemical Gas Sensors

Photocatalytic hydrogen production is considered a promising approach to generating clean sustainable energy. However, the conventional co-catalyst (e.g., Pt) used in photocatalytic hydrogen production is high-cost and difficult to obtain. Here, we designed and prepared a ternary nanocomposite MXene@Au@CdS, which can be used in the field of efficient and excellent photocatalytic hydrogen production. The MXene@Au@CdS has a hydrogen production rate of 17,070.43 μmol g−1 h−1 (tested for 2 h), which is 1.85 times that of pure CdS nanomaterials. The improved hydrogen production performance of the MXene@Au@CdS is attributed to: (i) MXene provides more active adsorption sites and reaction centers for Au and CdS nanoparticles; (ii) the synergistic effect of Au’s strong surface plasmon resonance expands the optical response range of CdS. Therefore, this work solves the problem of the solid connection between the surface functional groups of photocatalyst, and achieves rapid interface charge transfer and long-term stability during the hydrogen production.

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Facile preparation of self-assembled MXene@Au@CdS nanocomposite with enhanced photocatalytic hydrogen production activity

Herein, we report the synthesis of metal (Pt and Au) and metal alloy (PtAu) nanoparticles (NPs)-integrated graphitic carbon nitride (g-C3N4) hybrids using a facile solvothermal route for water-splitting application. The metal and metal alloy NPs with varying percentages of Pt and Au are found to be in the size range of 3-5 nm and uniformly distributed on the g-C3N4 sheets. The metal and metal alloy NPs act as cocatalyst for g-C3N4 to enhance the photocatalytic activity for hydrogen (H2) generation through higher light absorption and efficient charge separation. The alloy composition plays an important role to maximize the photoactivity, with an optimized PtAu/g-C3N4 sample delivered 1009 μmol g-1 h-1 of H2. The visible light assisted photocatalytic H2 evolution is further investigated with the optimized PtAu alloy NPs-integrated g-C3N4. This study presents a robust, stable, and easily synthesizable PtAu/g-C3N4 hybrid material as a promising photocatalyst for H2 generation through water splitting.

Bimetallic PtAu Alloy Nanoparticles-Integrated g-C3N4 Hybrid as an Efficient Photocatalyst for Water-to-Hydrogen Conversion.

Poly(ethylene imine) (PEI) has abundant amino groups in a macromolecular chain and can be used as a graft source for metal nanocomposites, which shows excellent ability to form stable complexes with heavy metal ions. In this work, a simple and convenient method was used to make PEI into a stable hydrogel with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide-N-hydroxysuccinimide and subsequently coprecipitate with silver nitrate solution or palladium chloride solution to form metal-loaded composite hydrogels. In addition, the characterizations of composite hydrogels were investigated by scanning electron microscopy, specific surface area tests (Brunauer-Emmett-Teller), X-ray photoelectron spectroscopy, and ultraviolet spectroscopy. The properties of composite hydrogels on the catalytic reduction of 4-nitrophenol were studied. The results showed that the composite hydrogels could be easily separated from the water environment, which indicated the large-scale potential application in organic catalytic degradation and wastewater treatment.

Facile Synthesis of Ag/Pd Nanoparticle-Loaded Poly(ethylene imine) Composite Hydrogels with Highly Efficient Catalytic Reduction of 4-Nitrophenol

The effective synthesis and self-assembly of nanocomposites were of key importance for a broad range of nanomaterial applications. In this work, new carbon nanotube (CNT)-Cu2O nanocomposites were successfully synthesized via a facile approach. CNT was selected as the anchoring substrate to load Cu2O nanoparticles to prepare composite catalysts with well stability and good reusability. It is discovered that the prepared CNT-Cu2O nanocomposite materials could be effectively controlled via regulating preparation temperature and time without the use of any stabilizing agents. The nanostructures of synthesized composites were well characterized by many techniques, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). And the prepared CNT-Cu2O nanocomposites with optimized preparation conditions as new catalyst displayed excellent catalytic performance on the reduction reaction of p-nitrophenol, demonstrating potential applications for environmental governance and composite materials.

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Facile Preparation of Carbon Nanotube-Cu2O Nanocomposites as New Catalyst Materials for Reduction of P-Nitrophenol.

The excellent physical and chemical properties of cyclodextrin polymer (poly-CD)/azobenzene-modified polyacrylic acid (PAA-Azo) binary composite hydrogels have been designed and prepared. The prepared hydrogels were subjected to a variety of characterizations, including scanning electron microscopy, ultraviolet spectroscopy, circular dichroism spectroscopy, infrared spectroscopy, rheological properties, and specific surface area tests. It was found that the obtained hydrogels have the cross-linked three-dimensional porous network nanostructures, and the formed composite poly-CD/PAA-Azo hydrogel can basically be shear thinned and have good recovery performance. A process of gel–sol transition can occur when the gel has a stimulatory response under UV light irradiation. In addition, such excellent properties of hydrogels exhibit different mechanisms in the adsorption of organic molecules that are harmful to the environment, such as bisphenol A (BPA) and methylene blue (MB). The polymeric hydrogel serves as ...

Self-Assembled Hydrogels Based on Poly-Cyclodextrin and Poly-Azobenzene Compounds and Applications for Highly Efficient Removal of Bisphenol A and Methylene Blue.



4-nitrophenol (4-NP) is one of the pollutants in sewage and harmful to human
health and the environment. Cu is a non-noble metal with catalytic reduction effect on nitro
compounds, and.has the advantages of simple preparation, abundant reserves, and low price. Carbon
nanotubes (CNT) are widely used for substrate due to their excellent mechanical stability and high
surface area. In this study, a simple method to prepare CNT-Cu2O by controlling different reaction
time was reported. The prepared nanocomposites were used to catalyze 4-NP.



CNTs and CuCl2 solution were put into a beaker, and then ascorbic acid and NaOH were
added while continuously stirring. The reaction was carried out for a sufficiently long period of time
at 60°C. The prepared samples were dried in a vacuum at 50°C for 48 h after washing with ethyl
alcohol and deionized water.



Nanostructures of these composites were characterized by scanning electron microscope and
transmission electron microscopy techniques, and the results at a magnification of 200 nanometers
showed that Cu2O was distributed on the surface of the CNTs. In addition, X-ray diffraction was
performed to further confirm the formation of Cu2O nanoparticles. The results of ultraviolet spectrophotometry
showed that the catalytic effect of the compound on 4-NP was obvious.



 CNTs acted as a huge template for loading Cu2O nanoparticles, which could improve
the stability and cycle performance of Cu2O. The formation of nanoparticles was greatly affected by
temperature and the appropriate concentration, showing great reducibility for the 4-NP reduction
reaction.


Yao Feng

Papers

In Situ Construction of Ag/TiO2/g-C3N4 Heterojunction Nanocomposite Based on Hierarchical Co-Assembly with Sustainable Hydrogen Evolution.

Facile Synthesis of Ag/Pd Nanoparticle-Loaded Poly(ethylene imine) Composite Hydrogels with Highly Efficient Catalytic Reduction of 4-Nitrophenol

Facile Preparation of Carbon Nanotube-Cu2O Nanocomposites as New Catalyst Materials for Reduction of P-Nitrophenol.

Self-Assembled Hydrogels Based on Poly-Cyclodextrin and Poly-Azobenzene Compounds and Applications for Highly Efficient Removal of Bisphenol A and Methylene Blue.

Facile Synthesis of Cu2O nanoparticle-loaded Carbon Nanotubes Composite Catalysts for Reduction of 4-Nitrophenol