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Co(OH)2/BiVO4 photoanode in tandem with a carbon-based perovskite solar cell for solar-driven overall water splitting
摘要： BiVO4 as a promising candidate photoanode material for PEC water splitting has been paid much attention due to its low cost, nontoxicity, high stability and narrow band gap energy of 2.4 eV. However, owing to its short carrier diffusion length and poor charge separation consequence the achieved efficiency of the BiVO4 photoanode is still limited. Herein, we addressed this issue by loading Co(OH)2 onto as-prepared BiVO4 to fabricate Co(OH)2/BiVO4 heterojunction photoanode via a simple solution impregnation method, in which Co(OH)2 as a modifier can increase interface charge separation efficiency from 44% of BiVO4 to 92% of Co(OH)2/BiVO4. As a result, the water-splitting photocurrent density was significantly enhanced from 1.57 mA/cm2 of BiVO4 to 4.52 mA/cm2 of Co(OH)2/BiVO4 at 1.23 V vs. RHE under 1-sun illumination. Further, the Co(OH)2/BiVO4 photoanode was assembled in tandem with a single sealed carbon-based PSC, and the resulting PV-PEC device showed a high STH efficiency of 4.6% and decent stability. The produced H2 and O2 gases were determined as ~68 μmol/cm2/h and ~34 μmol/cm2/h, respectively, corresponding to the 2:1 ratio of water splitting reaction with a faradaic efficiency of ~98%.
关键词： heterojunction photoanode,water splitting,tandem device,Co(OH)2/BiVO4
更新于2025-09-12 10:27:22
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Synthesis plasmonic Bi/BiVO4 photocatalysts with enhanced photocatalytic activity for degradation of tetracycline (TC)
摘要： In recent years, the excessive use of antibiotics has become a serious problem for human health. BiVO4 regarded as one of the most promising visible-light-driven photocatalysts was used to degrade the antibiotics. In this paper, we fabricated Bi/BiVO4 plasmonic photocatalysts which enhanced the photocatalytic activity of BiVO4 for degradation of tetracycline (TC) antibiotic. The Bi/BiVO4 photocatalysts were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and high-resolution transmission electron microscopy. In addition, the photocatalytic experiment results show that the 0.04-Bi/BiVO4 sample has the best photocatalytic activity for 2 times than the pure BiVO4 photocatalyst. The cycle experiments, after four repetitions of the experiments, showed the sample still maintained a high photocatalytic activity. Finally, the photocatalytic reaction mechanism was also studied by free radical capture experiments and electron paramagnetic resonance spectroscopy.
关键词： Photocatalysts,Tetracycline (TC),Bi/BiVO4,Plasmonic,Visible light
更新于2025-09-12 10:27:22
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Interfacial growth of the optimal BiVO4 nanoparticles onto self-assembled WO3 nanoplates for efficient photoelectrochemical water splitting
摘要： Photoelectrochemical water splitting is the most efficient green engineering approach to convert the sun light into hydrogen energy. The formation of high surface area core-shell heterojunction with enhanced light-harvesting efficiency, elevated charge separation, and transport are key parameters in achieving the ideal water splitting performance of the photoanode. Herein, we demonstrate a first green engineering interfacial growth of the BiVO4 nanoparticles onto self-assembled WO3 nanoplates forming WO3/BiVO4 core-shell heterojunction for efficient PEC water splitting performance. The three different WO3 nanostructures (nanoplates, nanobricks, and stacked nanosheets) were self-assembled on fluorine doped tin oxide glass substrates via hydrothermal route at various pH (0.8–1.2) of the solutions. In comparison to nanobricks and stacked nanosheets, WO3 nanoplates displayed considerably elevated photocurrent density. Moreover, a simple and low cost green approach of modified chemical bath deposition technique was established for the optimal decoration of a BiVO4 nanoparticles on vertically aligned WO3 nanoplates. The boosted photoelectrochemical current density of 1.7 mA cm?2 at 1.23 V vs. reversible hydrogen electrode (RHE) under AM 1.5 G illumination was achieved for the WO3/BiVO4 heterojunction which can be attributed to a suitable band alignment for the efficient charge transfer from BiVO4 to WO3, increased light harvesting capability of outer BiVO4 layer, and high charge transfer efficiency of WO3 nanoplates.
关键词： Green hydrogen,Photoelectrochemical water oxidation,WO3/BiVO4 heterojunction,Low cost,Core-shell
更新于2025-09-12 10:27:22
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Fabrication of a ternary heterostructure BiVO4 quantum dots/C60/g-C3N4 photocatalyst with enhanced photocatalytic activity
摘要： The BiVO4/C60/g-C3N4 ternary heterostructure composite was synthesized by a simple hydrothermal method by loading BiVO4 quantum dots (QDs) onto the surface of C60/g-C3N4, which has excellent photocatalytic activity under visible light irradiation (λ > 420 nm). The BiVO4/C60/g-C3N4 composite oxidatively degraded the organic pollutant Rhodamine B (Rh B) under visible light irradiation, due to the enhanced visible-light harvesting and the increased specific surface area after the addition of BiVO4 QDs. The composite material can effectively inhibit photoinduced electron-hole recombination, improve charge transfer efficiency, and significantly improve photocatalytic efficiency as compared with other single or binary components.
关键词： Photocatalysis,Carbon nitride,C60,Heterostructure,BiVO4
更新于2025-09-11 14:15:04
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Optimization Algorithms of Neural Networks for Traditional Time-Domain Equalizer in Optical Communications
摘要： Herein we report an e?ective Ru(NH3)6 3+/Ru(NH3)6 2+-mediated photoelectrochemical-chemical-chemical (PECCC) redox cycling ampli?cation (RCA) strategy toward enhanced triple signal ampli?cation for advanced split-type PEC immunoassay application. Speci?cally, alkaline phosphatase (ALP) label was con?ned via a sandwich immunorecognition to convert 4-aminophenyl phosphate to the signal reporter 4-aminophenol (AP), which was then directed to interact with Ru(NH3)6 2+ as a redox mediator and tris (2-carboxyethyl) phosphine (TCEP) as reducing agent in the detection bu?er. Upon illumination, the system was then operated upon the oxidation of Ru(NH3)6 2+ by the photogenerated holes on the Bi2S3/BiVO4 photoelectrode, starting the chain reaction in which the Ru(NH3)6 2+ was regenerated by Ru(NH3)6 3+-enabled oxidization of AP to p-quinoneimine, which was simultaneously recovered by TCEP. Exempli?ed by interleukin-6 (IL-6) as the analyte, the Ru(NH3)6 3+/Ru(NH3)6 2+-mediated, AP-involved PECCC RCA coupled with ALP enzymatic ampli?cation could achieve triple signal ampli?cation toward the ultrasensitive PEC IL-6 immunoassay. This protocol can be extended as a general basis for other numerous targets of interest. Besides, we believe this work could o?er a new perspective for the further exploration of advanced RCA-based PEC bioanalysis.
关键词： photoelectrochemical-chemical-chemical (PECCC) redox cycling ampli?cation (RCA),triple signal ampli?cation,Bi2S3/BiVO4 photoelectrode,Ru(NH3)6 3+/Ru(NH3)6 2+-mediated,PEC immunoassay
更新于2025-09-11 14:15:04
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Enhanced carrier transport and bandgap reduction in sulfur-modified BiVO <sub/>4</sub> photoanodes
摘要： Recent progress on bismuth vanadate (BiVO4) has shown it to be among the highest performing metal oxide photoanode materials. However, further improvement, especially in the form of thin film photoelectrodes, is hampered by its poor charge carrier transport and its relatively wide bandgap. Here, sulfur incorporation is used to address these limitations. A maximum bandgap decrease of ~0.3 eV is obtained, which increases the theoretical maximum solar-to-hydrogen efficiency from 9 to 12%. Hard X-ray photoelectron spectroscopy (HAXPES) measurements as well as density functional theory (DFT) calculations show that the main reason for the bandgap decrease is an upward shift of the valence band maximum. Time-resolved microwave conductivity measurements reveal an ~3 times higher charge carrier mobility compared to unmodified BiVO4, resulting in a ~70% increase in the carrier diffusion length. This work demonstrates that sulfur doping can be a promising and practical method to improve the performance of wide-bandgap metal oxide photoelectrodes.
关键词： bismuth vanadate,photoelectrochemical performance,charge carrier transport,BiVO4,sulfur incorporation,bandgap reduction
更新于2025-09-11 14:15:04
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Enhanced interaction in TiO<sub>2</sub>/BiVO<sub>4</sub> heterostructures via MXene Ti<sub>3</sub>C<sub>2</sub> derived 2D-Carbon for highly efficient visible-light photocatalysis
摘要： Heterostructured photocatalysts play a significant role in contaminants removal by decreasing the recombination of the photo-induced charges. Herein, we presented novel TiO2/C/BiVO4 ternary hybrids employing a two-dimensional (2D) layered Ti3C2 MXene precursor, overcoming lattice mismatching of TiO2/BiVO4 binary heterostructures simultaneously. Raman and XPS analyses proved the strongly coupling effects of TiO2, carbon and BiVO4 components, and the heterostructures were identified by HRTEM results. Moreover, the ternary TiO2/C/BiVO4 composites exhibit excellent photocatalytic performance of Rhodamine B degradation, which is about 4 times higher than pure BiVO4 and twice than binary TiO2/BiVO4 heterostructures, reaching a reaction constant of 13.7×10-3 min-1 under visible-light irradiation (λ>420 nm). In addition, the possible mechanism for dye elimination was proposed that RhB molecule was directly oxidized by photo-induced holes (h+) on the BiVO4 components and superoxide radical (O2·-) generated from conduction-band electrons of the heterostructures. This work will provide possibilities for developing visible-light responsive nanomaterials for efficient solar utilization.
关键词： Heterostructured TiO2/C/BiVO4,Hydrothermal,MXene,Photocatalysis
更新于2025-09-10 09:29:36
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An efficient tandem photoelectrochemical cell composed of FeOOH/TiO2/BiVO4 and Cu2O for self-driven solar water splitting
摘要： An integrated solar water splitting tandem cell without external bias was designed using a FeOOH modified TiO2/BiVO4 photoanode as a photoanode and p-Cu2O as a photocathode in this study. An apparent photocurrent (0.37 mA/cm2 at operating voltage of +0.36 VRHE) for the tandem cell without applied bias was measured, which is corresponding to a photoconversion efficiency of 0.46%. Besides, the photocurrent of FeOOH modified TiO2/BiVO4 and Cu2O photocathode (~0.07 mA/cm2 at +0.42 VRHE). Then we established a FeOOH modified TiO2/BiVO4-Cu2O two-electrode system and measured the current density-voltage curves under AM 1.5G illumination. The unassisted photocurrent density is 0.12 mA/cm2 and the corresponding amounts of hydrogen and oxygen evolved by the tandem PEC cell without bias are 2.36 mmol/cm2 and 1.09 mmol/cm2 after testing for 2.5 h. The photoelectrochemical (PEC) properties of the FeOOH modified TiO2/BiVO4 photoanode were further studied to demonstrate the electrons transport process of solar water splitting. This aspect provides a fundamental challenge to establish an unbiased and stabilized photoelectrochemical (PEC) solar water splitting tandem cell with higher solar-to-hydrogen efficiency.
关键词： Self-driven water splitting,PEC tandem cell,Solar hydrogen,Cu2O-BiVO4
更新于2025-09-10 09:29:36
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Sensitizing effects of BiVO4 and visible light induced production of highly reductive electrons in the TiO2/BiVO4 heterojunction
摘要： BiVO4 is an e?cient and stable visible active photoanode material. However, due to its unfavorable conduction band position which falls below the H2 reduction potential, it fails to carry out the complete water splitting reaction. On the other hand, larger band gap TiO2 is able to photocatalytically split water, thanks to its negative conduction band energy. Aiming at verifying the possibility of sensitizing TiO2 with BiVO4 and employing the so obtained composite material in photocatalytic water splitting under visible light, we prepared and photoelectrochemically characterized TiO2/BiVO4 heterojunction electrodes. The photocatalytic reduction of methyl viologen, an electron acceptor probe with a reduction potential close to that of protons, was used to evaluate the reducing ability of the photoactive materials under visible light. An apparently counterintuitive electron transfer from photoexcited BiVO4 to the TiO2 conduction band occurs in the TiO2/BiVO4 heterojunction, resulting in TiO2 sensitization and production of highly reductive electrons, which appears to be favored by the band alignment occurring at the heterojunction.
关键词： Methyl viologen reduction,Photo(electro)catalysis,TiO2,BiVO4,Heterojunction,Visible light sensitization
更新于2025-09-10 09:29:36
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Tuning in BiVO4/Bi4V2O10 porous heterophase nanospheres for synergistic photocatalytic degradation of organic pollutants
摘要： Heterophase junction construction is a powerful means of inhibiting recombination of photoinduced charge carriers. Herein, we prepared BiVO4/Bi4V2O10 porous heterophase nanospheres assembled by nanoflakes through a facile solvothermal process. The crystal structure of the porous nanospheres can be easily regulated from mixed phase of BiVO4 and Bi4V2O10 to pure BiVO4 by changing the solvothermal reaction time. The formation of heterophase junction BiVO4/Bi4V2O10 can greatly enhance the transfer and separation rate of photogenerated charge carriers. Meanwhile, the porous nanoflake-based nanosphere structure can enhance visible light utilization and organic pollutants adsorption. Benefiting from the synergy effects of these positive factors, the optimal BiVO4/Bi4V2O10 exhibits excellent visible light photocatalytic performance and cycling capability for the degradation of organic pollutants.
关键词： porous nanospheres,heterophase junction,pollutants degradation,BiVO4/Bi4V2O10,visible light photocatalysis
更新于2025-09-10 09:29:36