Showing papers by "Indian Association for the Cultivation of Science published in 2020"
TL;DR: The present review delineates, in short, the preparation, properties, and applications of different polymer and peptide hydrogels prepared in the past few years.
Abstract: In this review, we focus on the very recent developments on the use of the stimuli responsive properties of polymer hydrogels for targeted drug delivery, tissue engineering, and biosensing utilizing their different optoelectronic properties. Besides, the stimuli-responsive hydrogels, the conducting polymer hydrogels are discussed, with specific attention to the energy generation and storage behavior of the xerogel derived from the hydrogel. The electronic and ionic conducting gels have been discussed that have applications in various electronic devices, e.g., organic field effect transistors, soft robotics, ionic skins, and sensors. The properties of polymer hybrid gels containing carbon nanomaterials have been exemplified here giving attention to applications in supercapacitors, dye sensitized solar cells, photocurrent switching, etc. Recent trends in the properties and applications of some natural polymer gels to produce thermal and acoustic insulating materials, drug delivery vehicles, self-healing material, tissue engineering, etc., are discussed. Besides the polymer gels, peptide gels of different dipeptides, tripeptides, oligopeptides, polypeptides, cyclic peptides, etc., are discussed, giving attention mainly to biosensing, bioimaging, and drug delivery applications. The properties of peptide-based hybrid hydrogels with polymers, nanoparticles, nucleotides, fullerene, etc., are discussed, giving specific attention to drug delivery, cell culture, bio-sensing, and bioimaging properties. Thus, the present review delineates, in short, the preparation, properties, and applications of different polymer and peptide hydrogels prepared in the past few years.
228 citations
TL;DR: In this article, the authors explicitly demonstrate the consequences of this observation on brane world black holes, characterized by existence of a negative tidal charge, possibly marking a deviation from general relativity.
Abstract: The recent observation of the shadow of the supermassive black hole M87*, located at the center of the M87 galaxy, by the Event Horizon Telescope Collaboration has opened up a new window to probe the strong gravity regime. In this paper, we explicitly demonstrate the consequences of this observation on brane world black holes, characterized by existence of a negative tidal charge. Our results based on three observables associated with the shadow, namely, angular diameter, deviation from circularity, and axis ratio reveal that the existence of a negative tidal charge is more favored, possibly marking a deviation from general relativity.
176 citations
TL;DR: A general method to synthesize benzene dicarboxylic acid (BDC)-based MOFs with hierarchical 3D morphologies composed of 2D nanosheets or nanoplates with good selectivity with low limit of detection, and fast response time is reported.
Abstract: Two-dimensional metal–organic frameworks (2D MOFs) are an attractive platform to develop new kinds of catalysts because of their structural tunability and large specific surface area that exposes numerous active sites. In this work, we report a general method to synthesize benzene dicarboxylic acid (BDC)-based MOFs with hierarchical 3D morphologies composed of 2D nanosheets or nanoplates. In our proposed strategy, acetonitrile helps solvate the metal ions in solution and affects the morphology, while polyvinylpyrrolidone (PVP) serves as a shape-control agent to assist in the nucleation and growth of MOF nanosheets. PVP also acts as a depletion agent to drive the assembly of the hierarchical sheet/plate-like M-BDC under solvothermal conditions. Further, we also demonstrate the flexibility of the proposed method using numerous coordinating metal ions (M = Cu, Mn, Ni, and Zr). The potential of these MOFs for electrochemical glucose sensing is examined using the hierarchical sheet-like Ni-BDC MOF as the optimum sample. It drives the electrocatalytic oxidation of glucose over a wide range (0.01 mM to 0.8 mM) with high sensitivity (635.9 μA mM−1 cm−2) in the absence of modification with carbon or the use of conductive substrates. It also demonstrates good selectivity with low limit of detection (LoD = 6.68 μM; signal/noise = 3), and fast response time (<5 s).
167 citations
TL;DR: In this article, the authors summarized several homogeneous catalytic processes involving the nucleophilic addition of CO2, resulting in C-C and C-H bond formation leading to the synthesis of 2-oxazolidinones, aminals, terminal carboxylated products and indolelactone derivatives that are potentially sound for the pharmaceutical industry.
143 citations
TL;DR: Covalent organic frameworks (COFs) have attracted surging interest lately due to their wide potential in several frontline application areas like gas storage, sensing, photovoltaics, fuel cells, ac...
Abstract: Covalent organic frameworks (COFs) have attracted surging interest lately due to their wide potential in several frontline application areas like gas storage, sensing, photovoltaics, fuel cells, ac...
116 citations
TL;DR: In this article, the authors highlight the attractive features of the applications of mechanochemistry via ball milling in asymmetric organic syntheses in order to attract the attention of a wider section of the synthesis community.
98 citations
TL;DR: In this article, the authors show that the drive frequency acts as a tuning parameter for several reentrant transitions between ergodic and weak ergodicity breaking regimes in a periodically driven Rydberg chain.
Abstract: The presence of quantum scars, athermal eigenstates of a many-body Hamiltonian with finite-energy density, leads to an absence of ergodicity and long-time coherent dynamics starting from initial states that have a high overlap with scars as experimentally observed in a chain of ultracold Rydberg atoms. We show, via study of a periodically driven Rydberg chain, that the drive frequency acts as a tuning parameter for several reentrant transitions between ergodic and weak ergodicity breaking regimes. The former regime shows rapid thermalization of correlation functions and absence of scars in the Floquet spectrum of the system. The latter regime, in contrast, has scars; they lead to long-time coherent dynamics of correlation functions. We provide an analytical explanation of the existence of these regimes by going beyond a high-frequency Magnus expansion and using a novel perturbative approach valid at large drive amplitudes to derive a Floquet Hamiltonian which qualitatively explains the behavior of the driven system at arbitrary frequencies. We also discuss experiments involving finite Rydberg chains which can validate our theory. Our results demonstrate the possibility of drive-frequency-induced tuning between ergodic and weak ergodicity breaking dynamics in a disorder-free quantum many-body system.
91 citations
90 citations
TL;DR: In this paper, the authors bring together two nanostructures of different materials in a single building block to create a new platform where both can share their electronic and optical characteristics.
Abstract: Bringing together two nanostructures of different materials in a single building block can create a new platform where both can share their electronic and optical characteristics. While these have ...
89 citations
TL;DR: In this article, the fabrication of three different metal phosphates, e.g. Co-phosphate (CoPO), Ni-ph phosphate (NiPO), and Ni−Co-phophosphate(NiCoPO) using the corresponding metal sources and phosphoric acid as a phosphorus source under hydrothermal conditions without using any structure-directing agent.
Abstract: Due to unique structural porosity, low-cost, and good catalytic activity, oxygen evolution reactions over 3d transition elements have gained immense attention in recent years. Herein, we report the fabrication of three different metal phosphates, e. g. Co-phosphate (CoPO), Ni-phosphate (NiPO), and Ni−Co-phosphate (NiCoPO) using the corresponding metal sources and phosphoric acid as a phosphorus source under hydrothermal conditions without using any structure-directing agent. Since the as-prepared metal-based phosphates exhibit high surface area with good interparticle porosity and contain transition metals in the material frameworks, these materials have been investigated for electrocatalytic oxygen evolution reaction (OER). Among the three metal phosphates, the as-synthesized CoPO catalyst shows efficient electrocatalytic activity toward OER, with an overpotential of 350 mV at 10 mA cm in 1.0 M KOH solution and a relatively low Tafel slope of 60.7 mV dec. The good electrocatalytic performance of CoPO is attributed to its higher specific surface area and pore volume compared to other two catalysts. The CoPO-modified electrode also shows a high stability up to 15 h at a constant potential of 1.58 V, suggesting its promising future for OER catalysis.
89 citations
TL;DR: In this article, the authors use the holographic approach to describe the early-time acceleration and the late time acceleration eras of our universe in a unified manner, and the corresponding holographic cutoffs are determined in terms of the particle horizon and its derivatives.
Abstract: In the present paper, we use the holographic approach to describe the early-time acceleration and the late-time acceleration eras of our Universe in a unified manner. Such ``holographic unification'' is found to have a correspondence with various higher curvature cosmological models with or without matter fields. The corresponding holographic cutoffs are determined in terms of the particle horizon and its derivatives, or the future horizon and its derivatives. As a result, the holographic energy density we propose is able to merge various cosmological epochs of the Universe from a holographic point of view. We find the holographic correspondence of several $F(R)$ gravity models, including axion-$F(R)$ gravity models, of several Gauss-Bonnet $F(G)$ models and finally of $F(T)$ models, and in each case we demonstrate that it is possible to describe in a unified way inflation and late-time acceleration in the context of the same holographic model.
TL;DR: In this article, an overview on various designs and strategies of molecular building blocks for making solid-state emissive organic chromophores is presented. But achieving highly efficient solidstate emission (fluorescence), which leads to quenching of emission, is not an easy task because of molecular aggregation.
Abstract: Organic solid-state emissive materials have gained much attention in recent times due to their excellent optoelectronic properties leading to successful commercialization for organic electronics. But achieving highly efficient solid-state emission (fluorescence) from organic chromophores is not an easy task because of molecular aggregation which leads to quenching of emission. However, several strategies have been developed to generate efficient fluorescence emission in the solid state by suppressing the undesired molecular aggregation. In this review, first an overview on various designs and strategies of molecular building blocks for making solid-state emissive organic chromophores is presented. Among various strategies, the selection is focused on the use of either partially or fully twisted molecular building blocks or introduction of bulky substituents or employing a donor–acceptor type system, which can effectively reduce the intermolecular π–π stacking interaction and produce fluorescence emission in the solid state with high quantum yield. In this context, tuning and controlling of the fluorescence properties based on a single molecular building block is attractive to realize multicoloured emission and more advantageous for blending of different fluorescent materials in light emitting devices. In the second part, we illustrate several examples of colour tunable solid-state emissive organic materials that have been developed using a single molecular building block.
TL;DR: In this article, the superconducting pairing symmetry and pairing eigenvalue of the spin-fluctuation mediated pairing interaction underlines the crucial role of the interorbital Hubbard interaction in superconductivity, which turns out to be orbital selective.
Abstract: In the present Rapid Communication, we explore superconductivity in $\mathrm{Nd}\mathrm{Ni}{\mathrm{O}}_{2}$ and $\mathrm{La}\mathrm{Ni}{\mathrm{O}}_{2}$ employing a first-principles derived low-energy model Hamiltonian, consisting of two orbitals: Ni ${x}^{2}\ensuremath{-}{y}^{2}$, and an axial orbital. The axial orbital is constructed out of Nd/La $d$, Ni $3{z}^{2}\ensuremath{-}{r}^{2}$, and Ni $s$ characters. Calculation of the superconducting pairing symmetry and pairing eigenvalue of the spin-fluctuation mediated pairing interaction underlines the crucial role of the interorbital Hubbard interaction in superconductivity, which turns out to be orbital selective. The axial orbital brings in material dependence to the problem, making $\mathrm{Nd}\mathrm{Ni}{\mathrm{O}}_{2}$ different from $\mathrm{La}\mathrm{Ni}{\mathrm{O}}_{2}$, thereby controlling the interorbital Hubbard interaction-assisted superconductivity.
TL;DR: In this article, it was shown that magnetic frustration can lead to various classes of models with anomalous eigenstates embedded in the high-energy spectrum, called many-body quantum scars that live in a sea of typical eigen states.
Abstract: Magnetic frustration has been a source of inspiration to condensed matter physicists for many years, usually as a means to obtain exotic low-energy physics. Here, magnetic frustration is shown to lead to various classes of models with anomalous eigenstates embedded in the high-energy spectrum. These include states called many-body quantum scars that live in a sea of typical eigenstates. The work also shows that the entire spectrum can be scarred through a fragmentation of Hilbert space generated by frustration.
TL;DR: By exploration of α-halo ketone in amine as a halide precursor, different shaped nanocrystals without compromising the photoluminescence quantum yield (PLQY) are reported, and it has been concluded that primary ammonium ions led to six faceted nanocry crystals, but tertiary ammonium ion obtained in this case stabilized different group of facets.
Abstract: Bright lead halide perovskite nanocrystals, which have been extensively studied in the past 5 years, are mostly confined to a six faceted hexahedron (cube/platelet) shape. With variations of ligand, precursor, reaction temperature, and surface modification, their brightness has been enhanced and phase became stable, but ultimate nanocrystals still retained the hexahedron cube or platelet shape in most of the hot injection reactions. In contrast, by exploration of α-halo ketone in amine as a halide precursor, different shaped nanocrystals without compromising the photoluminescence quantum yield (PLQY) are reported. Confining to orthorhombic CsPbBr3, the obtained nanocrystals are stabilized by 12 facets ({200}, {020}, {112}) and led to 12 faceted rhombic dodecahedrons. These facets are absolutely different from six ({110}, {002}) equivalent facets of widely reported orthorhombic cube shaped CsPbBr3 nanocrystals. These also retained the colloidal and phase stability, as well as showed near unity PLQY. With further annealing, these are transformed to 26 faceted rhombicuboctahedrons by dissolving all their vertices. Importantly, these 12 faceted nanocrystals showed wide area self-assembly in most of the reactions. It has also been concluded that primary ammonium ions led to six faceted nanocrystals, but tertiary ammonium ions obtained in this case stabilized different group of facets. While perovskite nanocrystals were broadly confined to only nanocubes, these new nanocrystals with intense emission would certainly provide a new avenue for continuing their further research.
TL;DR: Details of the developments in the field established to date and supported by several established facts are reported and some unestablished stories or unsolved pathways surrounding the redox process and the importance of using a polar solvent which confused the understanding of the exclusive roles of perovskite nanocrystals in catalysis are discussed.
Abstract: In current research, halide perovskite nanocrystals have emerged as one of the potential materials for light-harvesting and photovoltaic applications. However, because of phase sensitivity, their exploration as photocatalysts in polar mediums is limited. It has been recently reported that these nanocrystals are capable of driving solar-to-chemical production through CO2 reduction. Using bare nanocrystals and also coupling in different supports, several reports on CO2 reduction in low polar mediums were reported, and the mechanism of involved redox processes was also proposed. Considering the importance of this upcoming catalytic activity of perovskites, in this Perspective, details of the developments in the field established to date and supported by several established facts are reported. In addition, some unestablished stories or unsolved pathways surrounding the redox process and the importance of using a polar solvent which confused the understanding of the exclusive roles of perovskite nanocrystals in catalysis are also discussed. Further, the future prospects of these materials that face challenges in dispersing in polar solvents, a key process in redox catalysis for CO2 reduction, are also discussed.
TL;DR: In this article, an extended matter bounce scenario is studied where the form of the scale factor is given by a ( t ) = ( a 0 t 2 + 1 ) n.
TL;DR: In this article, the authors investigated the existence of near-horizon variations in the ringdown phase of a black hole localized on the brane, carrying a negative tidal charge, and established the layout for future investigation of higher-dimensional effects in the signal.
Abstract: The holographic interpretation of the Randall-Sundrum model based on the adaptation of the $\mathrm{AdS}/\mathrm{CFT}$ correspondence to the braneworld scenario states that the black holes localized on the brane are quantum corrected. This can be better understood from the fact that the classical ${\mathrm{AdS}}_{5}$ bulk dynamics is dual to gravity coupled with conformal field theory (CFT) on the four-dimensional brane. Based on the backreaction of the CFT on the classical black hole geometry, localized on the brane, it is expected that there exist possible near-horizon modifications. This may result in the black hole horizon becoming partially reflective, thus giving rise to echoes in the ringdown signal in gravitational wave observations. In this paper, we investigate the existence of such echoes in the ringdown phase of a black hole localized on the brane, carrying a negative tidal charge, and establish the layout for future investigation of higher-dimensional effects in the ringdown signal. Confirmed detections of echoes at the current levels of instrumental sensitivity can constrain the dimensionless value of tidal charge to $|Q|\ensuremath{\lesssim}{M}^{2}$.
TL;DR: Using the defect engineering approach, metal-free–ligand-free nanocatalysts are developed, which convert CO2 to methane at the significant rates, scales, and stabilities and unlike metal catalysts, the defect-containing nanosilica showed significantly better stability.
Abstract: Active and stable metal-free heterogeneous catalysts for CO2 fixation are required to reduce the current high level of carbon dioxide in the atmosphere, which is driving climate change. In this work, we show that defects in nanosilica (E′ centers, oxygen vacancies, and nonbridging oxygen hole centers) convert CO2 to methane with excellent productivity and selectivity. Neither metal nor complex organic ligands were required, and the defect alone acted as catalytic sites for carbon dioxide activation and hydrogen dissociation and their cooperative action converted CO2 to methane. Unlike metal catalysts, which become deactivated with time, the defect-containing nanosilica showed significantly better stability. Notably, the catalyst can be regenerated by simple heating in the air without the need for hydrogen gas. Surprisingly, the catalytic activity for methane production increased significantly after every regeneration cycle, reaching more than double the methane production rate after eight regeneration cycles. This activated catalyst remained stable for more than 200 h. Detailed understanding of the role of the various defect sites in terms of their concentrations and proximities as well as their cooperativity in activating CO2 and dissociating hydrogen to produce methane was achieved.
TL;DR: A voltage-triggered charge disproportionation in thin molecular films of a metal–organic complex occurring in ambient conditions provides a technologically relevant molecular route for simultaneous realization of a ternary memristor and a binary memcapacitor, scalable down to a device area of 60 nm 2 .
Abstract: Electronic symmetry breaking by charge disproportionation results in multifaceted changes in the electronic, magnetic and optical properties of a material, triggering ferroelectricity, metal/insulator transition and colossal magnetoresistance. Yet, charge disproportionation lacks technological relevance because it occurs only under specific physical conditions of high or low temperature or high pressure. Here we demonstrate a voltage-triggered charge disproportionation in thin molecular films of a metal–organic complex occurring in ambient conditions. This provides a technologically relevant molecular route for simultaneous realization of a ternary memristor and a binary memcapacitor, scalable down to a device area of 60 nm2. Supported by mathematical modelling, our results establish that multiple memristive states can be functionally non-volatile, yet discrete—a combination perceived as theoretically prohibited. Our device could be used as a binary or ternary memristor, a binary memcapacitor or both concomitantly, and unlike the existing ‘continuous state’ memristors, its discrete states are optimal for high-density, ultra-low-energy digital computing. Charge disproportionation in thin molecular films of a metal–organic complex enables the realization of a ternary memristor and binary memcapacitor.
TL;DR: A review of the development of synthetic receptors for the recognition, sensing, extraction of phosphates, along with the biological applications of phosphate recognition which have emerged in the last five years (2015-to date) is provided in this article.
TL;DR: F facets and defects of perovskite nanocrystals are equally important for carrying out catalytic reactions as well as for suppression of carrier recombination in applications like catalysis.
Abstract: Light-emitting lead halide perovskite nanocrystals are typically obtained in a six-faceted cube shape. However, for applications such as catalysis, more active facets for the adsorption/desorption of reactants/products and the suppression of carrier recombination are essentially required. To meet these challenges, herein CsPbBr3 perovskite nanocrystals in cube and faceted noncube shapes were explored for photocatalytic reductions of CO2. Importantly, halide-deficient dim multifaceted noncube emitters having less than 1% photoluminescence quantum yields showed superior catalytic activity compared to that of bright halide-rich cube nanocrystals. Beyond these, hexapod-shaped nanocrystals were also explored, and these remained in an intermediate state. With the support of density functional theory, the adsorption and desorption probabilities of reactants/products on different facets were also calculated and correlated with experimental findings. These results indicated that facets and defects of perovskite nanocrystals are equally important for carrying out catalytic reactions.
TL;DR: This study highlights the accumulation of mutation on ORF3a in Indian SARS-CoV2 genomes which may provide the designing therapeutic approach against SAR's virulence property in Indian patients.
TL;DR: This article briefly discusses different types of fluorescent carbon dots and origin of their fluorescence, focuses on surface chemistry and functionalization which are relevant to intracellular probe development, and summarized various types of intrACEllular nanoprobes that are developed from fluorescence carbon dot.
Abstract: Fluorescent carbon dot has emerged as promising alternative of conventionally known quantum dot or molecular probe as potential intracellular imaging probe. In particular, in vitro Nanoparticle-Based Sensing.
TL;DR: In this article, the authors studied the dynamics of a periodically driven Rydberg chain starting from the state with zero rydberg excitations (vacuum state denoted by $|0\ensuremath{\rangle}$) using a square pulse protocol in the high drive amplitude limit.
Abstract: We study the dynamics of a periodically driven Rydberg chain starting from the state with zero Rydberg excitations (vacuum state denoted by $|0\ensuremath{\rangle}$) using a square pulse protocol in the high drive amplitude limit. We show, using exact diagonalization for finite system sizes $(L\ensuremath{\le}26)$, that the Floquet Hamiltonian of the system, within a range of drive frequencies that we chart out, hosts a set of quantum scars that have large overlap with the $|0\ensuremath{\rangle}$ state. These scars are distinct from their counterparts having high overlap with the maximal Rydberg excitation state $(|{\mathbb{Z}}_{2}\ensuremath{\rangle})$; they coexist with the latter class of scars and lead to persistent coherent oscillations of the density-density correlator starting from the $|0\ensuremath{\rangle}$ state. We also identify special drive frequencies at which the system undergoes perfect dynamic freezing, and we provide an analytic explanation for this phenomenon. Finally, we demonstrate that for a wide range of drive frequencies, the system reaches a steady state with subthermal values of the density-density correlator. The presence of such subthermal steady states, which are absent for dynamics starting from the $|{\mathbb{Z}}_{2}\ensuremath{\rangle}$ state, imply a weak violation of the eigenstate thermalization hypothesis in finite-sized Rydberg chains distinct from that due to the scar-induced persistent oscillations reported earlier. We conjecture that in the thermodynamic limit, such states may exist as prethermal steady states that show anomalously slow relaxation. We supplement our numerical results by deriving an analytic expression for the Floquet Hamiltonian using a Floquet perturbation theory in the high amplitude limit, which provides an analytic, albeit qualitative, understanding of these phenomena at arbitrary drive frequencies. We discuss experiments that can test our theory.
15 Jan 2020
TL;DR: Nanoparticles are widely used in photocatalytic degradation of toxic chemicals and photodynamic therapy of cells that involve light-induced generation of reactive oxygen species (ROS) followed by ROS-guided cell reprograming.
Abstract: Nanoparticles are widely used in photocatalytic degradation of toxic chemicals and photodynamic therapy of cells that involve light-induced generation of reactive oxygen species (ROS) followed by R...
TL;DR: GNC hydrogel could act as an ideal pH-monitoring and oral drug delivery system in near-neutral pH at the same time and could be useful for quantitative pH measurement.
Abstract: Delivery of therapeutics to the intestinal region bypassing the harsh acidic environment of the stomach has long been a research focus. On the other hand, monitoring a system's pH during drug delivery is a crucial diagnosis factor as the activity and release rate of many therapeutics depend on it. This study answered both of these issues by fabricating a novel nanocomposite hydrogel for intestinal drug delivery and near-neutral pH sensing at the same time. Gelatin nanocomposites (GNCs) with varying concentrations of carbon dots (CDs) were fabricated through simple solvent casting methods. Here, CDs served a dual role and simultaneously acted as a cross-linker and chromophore, which reduced the usage of toxic cross-linkers. The proposed GNC hydrogel sample acted as an excellent pH sensor in the near-neutral pH range and could be useful for quantitative pH measurement. A model antibacterial drug (cefadroxil) was used for the in vitro drug release study at gastric pH (1.2) and intestinal pH (7.4) conditions. A moderate and sustained drug release profile was noticed at pH 7.4 in comparison to the acidic medium over a 24 h study. The drug release profile revealed that the pH of the release medium and the percentage of CDs cross-linking influenced the drug release rate. Release data were compared with different empirical equations for the evaluation of drug release kinetics and found good agreement with the Higuchi model. The antibacterial activity of cefadroxil was assessed by the broth microdilution method and found to be retained and not hindered by the drug entrapment procedure. The cell viability assay showed that all of the hydrogel samples, including the drug-loaded GNC hydrogel, offered acceptable cytocompatibility and nontoxicity. All of these observations illustrated that GNC hydrogel could act as an ideal pH-monitoring and oral drug delivery system in near-neutral pH at the same time.
TL;DR: Site-specific elemental analyses show the Ag:Ni compositional variation, where the apex and edges of the decahedra are Ag-rich thereby exposing Ni onto the faces to achieve maximum charge transport for an exceptional pH universal HER activity, and density functional theory calculations elucidate the relative H-atom adsorption capability of the Ni centers as a function of their proximity to Ag atom.
Abstract: Five-fold intertwined Agx Ni1-x (x=0.01-0.25) heterogeneous alloy nanocrystal (NC) catalysts, prepared through unique reagent combinations, are presented. With only ca. 5 at % Ag (AgNi-5), Pt-like activity has been achieved at pH 14. To reach a current density of 10 mA cm-2 the extremely stable AgNi-5 requires an overpotential of 24.0±1.2 mV as compared to 20.1±0.8 mV for 20 % Pt/C, both with equal catalyst loading of 1.32 mg cm-2 . The turnover frequency (TOF) is as high as 2.1 H2 s-1 at 50 mV (vs. RHE). Site-specific elemental analyses show the Ag:Ni compositional variation, where the apex and edges of the decahedra are Ag-rich, thereby exposing Ni onto the faces to achieve maximum charge transport for an exceptional pH universal HER activity. DFT calculations elucidate the relative H-atom adsorption capability of the Ni centers as a function of their proximity to Ag atom.
TL;DR: In this article, three metal-doped organic-inorganic hybrid nanomaterials have attracted substantial attention for their high catalytic activity in the electrochemical oxygen evolution reaction (OER), using iminodi(methylphosphonic acid) as an organophosphorous precursor via a hydrothermal nontemplated synthetic route.
TL;DR: In this article, the authors summarized the development of the photoelectrochemical (PEC) based water splitting processes with respect to the efficiency and stability of the PEs and provided new paths for the establishment of a sustainable, renewable, and clean energy economy.