Browse
Submit Data
Databases
API
Help

Dataset Information

27 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

BiVO₄/TiO₂(N₂) Nanotubes Heterojunction Photoanode for Highly Efficient Photoelectrocatalytic Applications.

ABSTRACT:

Abstract

We report the development of a novel visible response BiVO₄/TiO₂(N₂) nanotubes photoanode for photoelectrocatalytic applications. The nitrogen-treated TiO₂ nanotube shows a high carrier concentration rate, thus resulting in a high efficient charge transportation and low electron-hole recombination in the TiO₂-BiVO₄. Therefore, the BiVO₄/TiO₂(N₂) NTs photoanode enabled with a significantly enhanced photocurrent of 2.73 mA cm^-2 (at 1 V vs. Ag/AgCl) and a degradation efficiency in the oxidation of dyes under visible light. Field emission scanning electron microscopy, X-ray diffractometry, energy-dispersive X-ray spectrometer, and UV-Vis absorption spectrum were conducted to characterize the photoanode and demonstrated the presence of both metal oxides as a junction composite.

Graphical abstract

Visible-light response BiVO₄/TiO₂(N₂) naontubes photoelectrode was fabricated for photoelectrochemical water splitting and organic degradation in this paper.

SUBMITTER: Wang R

PROVIDER: S-EPMC6223793 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Efficient photoelectrochemical water oxidation using a TiO2 nanosphere-decorated BiVO4 heterojunction photoanode.

Project description:Constructing heterojunctions by coupling dissimilar semiconductors is a promising approach to boost charge separation and charge transfer in photoelectrochemical (PEC) water splitting. In this work, we fabricated a highly efficient TiO2/BiVO4 heterojunction photoanode for PEC water oxidation via a simple hydrothermal method. The resulting heterojunction photoanodes show enhanced PEC performance compared to the bare BiVO4 due to the simultaneous improvements in charge separation and charge transfer. Under simulated sunlight illumination (AM 1.5G, 100 mW cm-2), a high photocurrent of 3.3 mA cm-2 was obtained at 1.23 V (vs. the reversible hydrogen electrode (RHE)) in a neutral solution, which exceeds those attained by the previously reported TiO2/BiVO4 heterojunctions. When a molecular Co-cubane catalyst was immobilized onto the electrode, the performance of the TiO2/BiVO4 heterojunction photoanode can be further improved, achieving a higher photocurrent density of 4.6 mA cm-2 at 1.23 V, an almost three-fold enhancement over that of the bare BiVO4. These results engender a promising route to designing an efficient photoelectrode for PEC water splitting.

| S-EPMC9091981 | biostudies-literature

Porous BiVO4/Boron-Doped Diamond Heterojunction Photoanode with Enhanced Photoelectrochemical Activity.

Project description:Constructing heterojunction is an attractive strategy for promoting photoelectrochemical (PEC) performance in water splitting and organic pollutant degradation. Herein, a novel porous BiVO4/Boron-doped Diamond (BiVO4/BDD) heterojunction photoanode containing masses of ultra-micro electrodes was successfully fabricated with an n-type BiVO4 film coated on a p-type BDD substrate by magnetron sputtering (MS). The surface structures of BiVO4 could be adjusted by changing the duration of deposition (Td). The morphologies, phase structures, electronic structures, and chemical compositions of the photoanodes were systematically characterized and analyzed. The best PEC activity with the highest current density of 1.8 mA/cm2 at 1.23 VRHE was achieved when Td was 30 min, and the sample showed the highest degradation efficiency towards tetracycline hydrochloride degradation (TCH) as well. The enhanced PEC performance was ascribed to the excellent charge transport efficiency as well as a lower carrier recombination rate, which benefited from the formation of BiVO4/BDD ultra-micro p-n heterojunction photoelectrodes and the porous structures of BiVO4. These novel photoanodes were expected to be employed in the practical PEC applications of energy regeneration and environmental management in the future.

| S-EPMC9415291 | biostudies-literature

Photoelectrocatalytic C-H halogenation over an oxygen vacancy-rich TiO2 photoanode.

Project description:Photoelectrochemical cells are emerging as powerful tools for organic synthesis. However, they have rarely been explored for C-H halogenation to produce organic halides of industrial and medicinal importance. Here we report a photoelectrocatalytic strategy for C-H halogenation using an oxygen-vacancy-rich TiO2 photoanode with NaX (X=Cl-, Br-, I-). Under illumination, the photogenerated holes in TiO2 oxidize the halide ions to corresponding radicals or X2, which then react with the substrates to yield organic halides. The PEC C-H halogenation strategy exhibits broad substrate scope, including arenes, heteroarenes, nonpolar cycloalkanes, and aliphatic hydrocarbons. Experimental and theoretical data reveal that the oxygen vacancy on TiO2 facilitates the photo-induced carriers separation efficiency and more importantly, promotes halide ions adsorption with intermediary strength and hence increases the activity. Moreover, we designed a self-powered PEC system and directly utilised seawater as both the electrolyte and chloride ions source, attaining chlorocyclohexane productivity of 412 µmol h-1 coupled with H2 productivity of 9.2 mL h-1, thus achieving a promising way to use solar for upcycling halogen in ocean resource into valuable organic halides.

| S-EPMC8602285 | biostudies-literature

Charge Transport Enhancement in BiVO4 Photoanode for Efficient Solar Water Oxidation.

Project description:Photoelectrochemical (PEC) water splitting in a pH-neutral electrolyte has attracted more and more attention in the field of sustainable energy. Bismuth vanadate (BiVO4) is a highly promising photoanode material for PEC water splitting. Additionally, cobaltous phosphate (CoPi) is a material that can be synthesized from Earth's rich materials and operates stably in pH-neutral conditions. Herein, we propose a strategy to enhance the charge transport ability and improve PEC performance by electrodepositing the in situ synthesis of a CoPi layer on the BiVO4. With the CoPi co-catalyst, the water oxidation reaction can be accelerated and charge recombination centers are effectively passivated on BiVO4. The BiVO4/CoPi photoanode shows a significantly enhanced photocurrent density (Jph) and applied bias photon-to-current efficiency (ABPE), which are 1.8 and 3.2 times higher than those of a single BiVO4 layer, respectively. Finally, the FTO/BiVO4/CoPi photoanode displays a photocurrent density of 1.39 mA cm-2 at 1.23 VRHE, an onset potential (Von) of 0.30 VRHE, and an ABPE of 0.45%, paving a potential path for future hydrogen evolution by solar-driven water splitting.

| S-EPMC10180425 | biostudies-literature

Embedding laser generated nanocrystals in BiVO4 photoanode for efficient photoelectrochemical water splitting.

Project description:Addressing the intrinsic charge transport limitation of metal oxides has been of significance for pursuing viable PEC water splitting photoelectrodes. Growing a photoelectrode with conductive nanoobjects embedded in the matrix is promising for enhanced charge transport but remains a challenge technically. We herein show a strategy of embedding laser generated nanocrystals in BiVO4 photoanode matrix, which achieves photocurrent densities of up to 5.15 mA cm-2 at 1.23 VRHE (from original 4.01 mA cm-2) for a single photoanode configuration, and 6.22 mA cm-2 at 1.23 VRHE for a dual configuration. The enhanced performance by such embedding is found universal owing to the typical features of laser synthesis and processing of colloids (LSPC) for producing ligand free nanocrystals in desired solvents. This study provides an alternative to address the slow bulk charge transport that bothers most metal oxides, and thus is significant for boosting their PEC water splitting performance.

| S-EPMC6565742 | biostudies-literature

Highly Efficient Photoelectrocatalytic Reduction of CO2 to Methanol by a p-n Heterojunction CeO2/CuO/Cu Catalyst.

Project description:Photoelectrocatalytic reduction of CO2 to fuels has great potential for reducing anthropogenic CO2 emissions and also lessening our dependence on fossil fuel energy. Herein, we report the successful development of a novel photoelectrocatalytic catalyst for the selective reduction of CO2 to methanol, comprising a copper catalyst modified with flower-like cerium oxide nanoparticles (CeO2 NPs) (a n-type semiconductor) and copper oxide nanoparticles (CuO NPs) (a p-type semiconductor). At an applied potential of - 1.0 V (vs SCE) under visible light irradiation, the CeO2 NPs/CuO NPs/Cu catalyst yielded methanol at a rate of 3.44 μmol cm-2 h-1, which was approximately five times higher than that of a CuO NPs/Cu catalyst (0.67 μmol cm-2 h-1). The carrier concentration increased by ~ 108 times when the flower-like CeO2 NPs were deposited on the CuO NPs/Cu catalyst, due to synergistic transfer of photoexcited electrons from the conduction band of CuO to that of CeO2, which enhanced both photocatalytic and photoelectrocatalytic CO2 reduction on the CeO2 NPs. The facile migration of photoexcited electrons and holes across the p-n heterojunction that formed between the CeO2 and CuO components was thus critical to excellent light-induced CO2 reduction properties of the CeO2 NPs/CuO NPs/Cu catalyst. Results encourage the wider application of composite semiconductor electrodes in carbon dioxide reduction.

| S-EPMC7770658 | biostudies-literature

Highly efficient hamburger-like nanostructure of a triadic Ag/Co3O4/BiVO4 photoanode for enhanced photoelectrochemical water oxidation.

Project description:The combination of a semiconductor heterojunction and oxygen evolution cocatalyst (OEC) is an important strategy to improve photoelectrochemical (PEC) water oxidation. Herein, a novel hamburger-like nanostructure of a triadic photoanode composed of BiVO4 nanobulks, Co3O4 nanosheets and Ag nanoparticles (NPs), that is, Ag/Co3O4/BiVO4, was designed. In our study, an interlaced 2D ultrathin p-type Co3O4 OEC layer was introduced onto n-type BiVO4 to form a p-n Co3O4/BiVO4 heterojunction with an internal electric field (IEF) in order to facilitate charge transport. Then the modification with Ag NPs can significantly facilitate the separation and transport of photogenerated carriers through the surface plasma resonance (SPR) effect, inhibiting the electron-hole recombination. The resulting Ag/Co3O4/BiVO4 photoanodes exhibit largely enhanced PEC water oxidation performance: the photocurrent density of the ternary photoanode reaches up to 1.84 mA cm-2 at 1.23 V vs. RHE, which is 4.60 times higher than that of the pristine BiVO4 photoanode. The IPCE value is 2.83 times higher than that of the pristine BiVO4 at 400 nm and the onset potential has a significant cathodic shift of 550 mV for the ternary well-constructed photoanode.

| S-EPMC9058554 | biostudies-literature

Efficient charge separation and transfer of a TaON/BiVO4 heterojunction for photoelectrochemical water splitting.

Project description:The separation and transfer of photogenerated electron-hole pairs in semiconductors is the key point for photoelectrochemical (PEC) water splitting. Here, an ideal TaON/BiVO4 heterojunction electrode was fabricated via a simple hydrothermal method. As BiVO4 and TaON were in well contact with each other, high performance TaON/BiVO4 heterojunction photoanodes were constructed. The photocurrent of the 2-TaON/BiVO4 electrode reached 2.6 mA cm-2 at 1.23 V vs. RHE, which is 1.75 times as that of the bare BiVO4. TaON improves the PEC performance by simultaneously promoting the photo-generated charge separation and surface reaction transfer. When a Co-Pi co-catalyst was integrated onto the surface of the 2-TaON/BiVO4 electrode, the surface water oxidation kinetics further improved, and a highly efficient photocurrent density of 3.6 mA cm-2 was achieved at 1.23 V vs. RHE. The largest half-cell solar energy conversion efficiency for Co-Pi/TaON/BiVO4 was 1.19% at 0.69 V vs. RHE, corresponding to 6 times that of bare BiVO4 (0.19% at 0.95 V vs. RHE). This study provides an available strategy to develop photoelectrochemical water splitting of BiVO4-based photoanodes.

| S-EPMC8697503 | biostudies-literature

The Self-Passivation Mechanism in Degradation of BiVO4 Photoanode.

Project description:BiVO4 is a promising photoanode material for solar-assisted water splitting in a photoelectrochemical cell but has a propensity to degrade. Investigations carried out here in 0.1 M Na2SO4 electrolyte showed that degradation is by dissolution of V in the electrolyte while Bi is retained on the anode probably in the form of solid Bi oxide (Bi2O3, Bi4O7). Accumulation of Bi oxide on the anode surface leads to passivation from further degradation. Thermodynamic modeling of possible degradation reactions has provided theoretical support to this mechanism. This self-passivation is accompanied by a decrease in photocurrent density, but it protects the anode against extensive photocorrosion and contributes to long-term stability. This is a more definitive understanding of degradation of BiVO4 during water splitting in a photoelectrochemical cell. This understanding is imperative for both fundamental and applied research.

| S-EPMC6744392 | biostudies-literature

Highly Efficient Photocatalytic Degradation of Hydrogen Sulfide in the Gas Phase Using Anatase/TiO2(B) Nanotubes.

Project description:Hydrogen sulfide (H2S) is a highly toxic and corrosive gas that causes a foul odor even at very low concentrations [several parts per billion (ppb)]. However, industrially discharged H2S has a concentration range of several tens of ppb to several parts per million (ppm), which conventional methods are unable to process. Therefore, advanced and sustainable methods for treating very low concentrations of H2S are urgently needed. TiO2-based photocatalysts are eco-friendly and have the ability to treat environmental pollutants, such as low-concentration gases, using light energy. However, there are no reports on H2S decomposition or oxidation at concentrations below several ppb. Therefore, in this study, we employed anatase/TiO2(B) nanotubes, which have a high specific surface area and an efficient charge-transfer interface, to treat H2S. We successfully reduced 10 ppm of H2S to 1 ppb or less at a kinetic rate of 75 μmol h-1 g-1. The suitability of our method was further demonstrated by the generation of sulfate ions and sulfur (as detected by X-ray photoelectron spectroscopy and ion chromatography), which are industrially useful as oxidation products, whereas sulfur dioxide, a harmful substance, was not produced. This is the first study to report H2S decomposition down to the ppb level, providing meaningful solutions for malodor problems and potential health hazards associated with H2S.

| S-EPMC9016837 | biostudies-literature