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Reduced graphene oxide/metallic MoSe2: Cu nanosheet nanostructures grown by a chemical process for highly efficient water splitting
摘要： The transition metal dichalcogenides with metallic 1T structure are attracting contemporary attention for applications in high-performance devices because of their peculiar optical and electrical properties. To date, one-step synthesis of 1T-MoSe2 is a challenge. This work presents a facile one-step synthesis of reduced graphene oxide/1T MoSe2: Cu nanosheets. The experiment results indicated that the MoSe2 prepared by simple chemical solution reaction possessed 1T structures. The reduced graphene oxide (RGO) incorporation and Cu doping did not obviously affect the phase structure but decreased the average particle size. The 1T structure, together with the Cu doping and interface effect between the MoSe2 and RGO, remarkably enhanced the conduction and photoconduction of the nanostructures. Thus, Cu doping and RGO incorporation also enhanced the hydrogen evolution catalytic activity and stability, making the RGO/MoS2: Cu nanosheet a most active and stable catalyst for hydrogen evolution.
关键词： MoSe2,Water splitting,Graphene,Metallic structure,Nanostructures
更新于2025-09-09 09:28:46
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High Photoconversion Efficiency Obtained from Novel TiO2 Photoanodes
摘要： High photoconversion efficiency for photoelectrochemical water splitting was obtained using nanocaves TiO2 and highly uniformed TiO2 nanotubes. The photoanodes were synthesized via electrochemical anodization of a titanium foil in a glycerol-based solution containing NH4F at 10 V. Pulse electrodeposition was used to incorporate Cu ions into the uniform TiO2 nanotubes. The photoconversion efficiency performance was examined under simulated visible light illumination (? ≥ 380 nm) in a 1 M solution of NaOH. The photocurrent density, the Mott-Schottky, the EIS, and the photoconversion efficiency measurements were determined. The highest photocurrent density i.e. 5.77 mA cm-2 at 1.23 V vs. RHE was obtained from nanocaves TiO2 photoanode. The incorporation of Cu resulted in a reduction in photocatalytic activity of the oxygen evaluation reaction (OER) and an increase of the hydrogen evolution reaction (HER).
关键词： Titanium dioxide nanotubes,water splitting,Photocurrent density,Photoelectrochemical,Anodization
更新于2025-09-09 09:28:46
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Synthesis of Uniform Ordered Mesoporous TiO2 Microspheres with Controllable Phase Junctions for Efficient Solar Water Splitting
摘要： As a benchmark photocatalyst, commercial P25-TiO2 has been widely used for various photocatalytic applications. However, the low surface area and poorly porous structure greatly limit its performance. Herein, uniform ordered mesoporous TiO2 microspheres (denoted as Meso-TiO2-X, X represents the rutile percentage in the resulted microspheres) with controllable anatase/rutile phase junctions and radially oriented mesochannels were synthesized by a coordination-mediated self-assembly approach. The anatase/rutile ratio in the resultant microspheres can be facilely adjusted as desired (rutile percentage: 0–100) by changing the concentrations of hydrochloric acid. As a typical one, the yielded Meso-TiO2-25 microspheres have a similar anatase/rutile ratio with commercial P25. But the surface area (78.6 m2 g–1) and pore volume (0.39 cm3 g–1) of the resultant microspheres are larger than that of commercial P25. When used as the photocatalysts for H2 generation, the Meso-TiO2-25 delivers a high solar-driven H2 evolution rate under air mass 1.5 global (AM 1.5G) and visible-light (λ > 400 nm), respectively, which are significantly larger than that of commercial P25. This coordination-mediated self-assembly method paves a new way toward the design and synthesis of high performance mesoporous photocatalysts.
关键词： water splitting,mesoporous TiO2,phase junctions,self-assembly,photocatalysis
更新于2025-09-09 09:28:46
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Interfacial Optimization of g-C3N4-based Z-Scheme Heterojunction toward Synergistic Enhancement of Solar-Driven Photocatalytic Oxygen Evolution
摘要： Exploring active catalyst materials for solar-driven photocatalytic water splitting into oxygen has proven extremely challenging, mostly due to poor oxygen-evolving efficiency originating from intrinsically sluggish oxygen evolution reaction (OER) kinetics. Ag3PO4 has been actively pursued as a promising photocatalyst for oxygen evolution from water-splitting. However, its low OER efficiency is a long standing problem. Both the construction of Z-scheme Ag3PO4-based composite photocatalytic systems and the optimization of surface morphology and interfacial contact in heterojunctions photocatalysts would be beneficial for boosting OER efficiency. Here we report on the fabrication of Ag3PO4/fish scale-like graphitic carbon nitride (g-C3N4) sheet composites with well-defined heterostructures and intimate interfacial contact driven by electrostatic assembly. The Ag3PO4/modified g-C3N4 composites photocatalyst reveals significantly enhanced oxygen-evolving activity under light-emitting diode (LED) illumination. Effective surface modification of g-C3N4, strong interfacial interactions between two semiconductors and tandem Z-scheme-type pathway for more efficient charge transfer synergistically accelerates the redox capability of Ag3PO4 for OER. This work may provide new insights into the design and construction of high-performance solar-driven Z-scheme photocatalytic water splitting systems.
关键词： water splitting,Z-scheme,photocatalytic oxygen evolution,g-C3N4,Ag3PO4
更新于2025-09-09 09:28:46
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NH2-MIL-125(Ti)/TiO2 Nanorod Heterojunction Photoanodes for Efficient Photoelectrochemical Water Splitting
摘要： A photoactive amine-functionalized Ti metal-organic framework (MOF) (MIL(125)-NH2(Ti)) layer is uniformly coated on vertically ordered TiO2 nanorods (NRs) via a facile hydrothermal reaction, and the performance of the heterojunction photoanode in photoelectrochemical (PEC) water splitting is studied. The photocurrent density of the MIL(125)-NH2/TiO2 NRs reaches 1.63 mA/cm2 at 1.23 V vs. a reversible hydrogen electrode under AM 1.5 G simulated sunlight illumination, which is ~2.7 times higher than that of pristine TiO2 NRs. The incident photon-to-electron conversion efficiency of the MIL(125)-NH2/TiO2 NRs improves significantly at λmax = 340 nm, implying the promotion of water oxidation through efficient light absorption and charge separation. The enhancement of the PEC activity in the TiO2 NRs caused by an MIL(125)-NH2 coating is discussed in relation to the surface area and elongated configuration of the TiO2 NRs, the band gap of MIL(125)-NH2(Ti), and the type (II) heterojunction. This study demonstrates the rational design of heterojunctions between the semiconductor and the MOF, which paves the way for new facile and general approaches to achieve a high efficiency in water splitting.
关键词： TiO2 nanorod,Photoelectrochemical water splitting,Photoanode,MIL(125)-NH2,Hydrothermal reaction
更新于2025-09-09 09:28:46
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Carbon dots modified WO2-NaxWO3 composite as UV-Vis-NIR broad spectrum-driven photocatalyst for overall water splitting
摘要： The utilization of solar energy and valid photocatalyst is one of the most effective strategies to achieve water splitting into hydrogen (H2) and oxygen (O2). Although enormous effort has been devoted to photocatalysts, the sunlight still cannot be fully utilized by the developed photocatalysts. It is important but remains challenging to develop a broad spectrum-driven photocatalyst for overall water splitting. Here, we design a UV-Vis-NIR broad spectrum-driven carbon dots modified WO2-NaxWO3 (WO2-NaxWO3-CDs) composite as photocatalyst for overall water splitting without requirement of any sacrificial agents or cocatalysts. When the concentration of CDs in the sample is 0.008 gCDs/gcatalyst, the WO2-NaxWO3-CDs shows the highest photocatalytic activity with stoichiometric ratio of H2/O2 evolutions and their rates are 0.05/0.02, 2.58/1.24, 4.74/2.28 μmol/h under UV (λ< 420 nm), visible (420 nm≤λ≤760 nm) and near-infrared (λ>760 nm) light irradiation, respectively. It is also impressive that the photocatalyst shows excellent stability for about 6 cycles of repetitive experiments. The WO2-NaxWO3-CDs composites functioned as broad spectrum-driven photocatalyst for overall water splitting should attribute to the synergistic effect of WO2-NaxWO3 and CDs, in which the WO2-NaxWO3 provides the suitable bandgap, while the CDs can enhance light absorption and accelerate separation efficiencies of photo-generated charge carriers.
关键词： CDs,overall water splitting,broad spectrum,WO2-NaxWO3,photocatalyst
更新于2025-09-09 09:28:46
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Pyrite-Type CoS2 Nanoparticles Supported on Nitrogen-Doped Graphene for Enhanced Water Splitting
摘要： It is extremely meaningful to develop cheap, highly efficient, and stable bifunctional electrocatalysts for both hydrogen and oxygen evolution reactions (HER and OER) to promote large-scale application of water splitting technology. Herein, we reported the preparation of CoS2 nanoparticles supported on nitrogen-doped graphene (CoS2@N-GN) by one-step hydrothermal method and the enhanced electrochemical efficacy for catalyzing hydrogen and oxygen in water electrolysis. The CoS2@N-GN composites are composed of nitrogen-doped graphene and CoS2 nanocrystals with the average size of 73.5 nm. Benefitting from the improved electronic transfer and synergistic effect, the as-prepared CoS2@N-GN exhibits remarkable OER and HER performance in 1.0 M KOH, with overpotentials of 243 mV for OER and 204 mV for HER at 10 mA cm?2, and the corresponding Tafel slopes of 51.8 and 108 mV dec?1, respectively. Otherwise, the CoS2@N-GN hybrid also presents superior long-term catalytic durability. Moreover, an alkaline water splitting device assembled by CoS2@N-GN as both anode and cathode can achieve a low cell voltage of 1.53 V at 60 ?C with a high faraday efficiency of 100% for overall water splitting. The tremendously enhanced electrochemical behaviors arise from favorable factors including small sized, homogenously dispersed novel CoS2 nanocrystals and coupling interaction with the underlying conductive nitrogen-doped graphene, which would provide insight into the rational design of transition metal chalcogenides for highly efficient and durable hydrogen and oxygen-involved electrocatalysis.
关键词： water splitting,HER/OER,graphene,nanoparticle,composite,cobalt sulfide
更新于2025-09-09 09:28:46
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Photochemical deposition of silver on Fe2O3 nanotubes prepared by anodization and exploring their photoelectrochemical activity
摘要： Novel silver-decorated Fe2O3 nanotubes (Ag/FeNT) have been synthesized by a simple, fast and efficient method. Fe2O3 nanotubes (FeNT) have been successfully synthesized on pure iron plates by electrochemical anodizing, followed by silver deposition on the surface of the nanotubes through photodeposition. Various instrumental techniques have been used to investigate the morphology, structure and optical properties of the prepared samples. In addition, the photoelectrochemical water splitting performance of the new electrodes has been studied. An increased photocurrent density and a greatly enhanced onset potential for photoelectrochemical activity have been shown by Ag/FeNT electrodes in comparison with bare FeNT. Silver-decorated Fe2O3 nanotube (sample Ag/FeNT1) shows an almost 2.5-fold increase in photocurrent compared with bare Fe2O3 nanotube. Efficient charge carrier separation, visible light sensitization due to Ag nanoparticles on Fe2O3 nanotube and enhanced electrical conductivity are responsible for the increase in the photoelectrochemical water splitting activity of Ag/FeNT.
关键词： Water splitting,Silver deposition,Fe2O3 nanotubes,Photoelectrochemical activity
更新于2025-09-09 09:28:46
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Nanoscale Materials in Water Purification || Photocatalysis of Graphene and Carbon Nitride-Based Functional Carbon Quantum Dots
摘要： Day by day, global energy demands increase due to the rapid consumption of depleting fossil fuels and environmental pollution. This has led to the search for materials capable of both energy conversion and elimination of environmental pollutants through the aid of renewable solar energy. This is a promising approach for meeting future energy requirements and eliminating environmental pollutants. In this pursuit, semiconductor photocatalysts have immense potential for solving both energy and environmental issues. To date, numerous semiconductor materials have been explored, including those of metal oxides, chalcogenides, borates, titanates, tungstates, vanadates, zirconates, oxyhalides, and metal-based interstitial compounds. However, the majority of these suffer from limitations such as complex synthesis procedures, limited light absorption range due to their wide band gap, high cost, and toxicity-related issues. Over the past decade, carbon-based nanomaterials have gained attention in the field of photocatalysis. Many recent articles have placed emphasis upon metal-free carbon-based photocatalytic systems for degradation of organic pollutants and hydrogen production from water splitting. The prime merit of these nanomaterials is that they originate from naturally abundant constituent elements such as carbon, nitrogen, and oxygen, making them more economical than their metal-based counterparts. Most reported carbon-based photocatalysts have tunable band gap energies, enhancing their optical absorption range. Band gap energy can be tuned by varying synthesis conditions and precursors, resulting in the formation of nanomaterials with different morphologies. The preparation procedures for most carbon-based nanomaterials are less complex than those of metal-based materials.
关键词： water splitting,energy conversion,semiconductor photocatalysts,graphene,carbon nitride,quantum dots,carbon-based nanomaterials,hydrogen production,solar energy,environmental pollutants,photocatalysis
更新于2025-09-09 09:28:46
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Nanostructured Titanium Dioxide Based on Titanium Alloys: Synthesis and Properties
摘要： Titanium dioxide (TiO2) has provoked a significant amount of scientific and technological interest due to their anticipated impact in the fields of photocatalysis, solar cells, lithium-ion battery electrodes, and biomedical devices. This is particularly apparent in the case of anodization and ion implantation for modifying Ti-based alloys. However, the lack of sufficient solar light absorption and limited hole diffusion significantly affect the performance of TiO2 in photocatalysis. Moreover, the biocompatibility and corrosion resistance of Ti-based biomedical device need to be enhanced to achieve a longer service life. In the present review, the MOx prepared by anodization is described first. Then, the electrolyte parameters during anodization are assessed by comparing various electrolytes including ethylene glycol, glycerol, formamide, and aqueous electrolytes. Additionally, the effects of ion implantation on the surface of Ti-based alloy are outlined. By analyzing the impact on various synthetic method and modification strategies of nanostructured TiO2, the essential elements of suitable in situ doping ratio and ion implantation dose are addressed. Finally, the outlook for anodization and ion implantation for constructing nanostructured TiO2 is discussed, highlighting challenges and key areas for future research and development.
关键词： Anodization,Water Splitting,Biocompatibility,TiO2-Based Ti Alloy,Ion Implantation
更新于2025-09-09 09:28:46