Bismuth vanadate is a promising photoanode with a set of intrinsic limitations for water oxidation and photoelectrochemical degradation of organic pollution. FeOOH/P:BiVO₄/rGO composite with a considerably small charge-transfer resistance was successfully developed by doping the BiVO₄ lattice with phosphate (P:BiVO₄), photo-depositing FeOOH nanoparticles on P:BiVO₄ nanoparticles, and grafting reduced graphene oxide (rGO) onto the surface of P:BiVO₄, in that order. This composite photoelectrode significantly improves photoelectrochemical performance originating from its effective suppression on electron-hole recombination and charge transfer at the semiconductor/electrolyte interface. The photoelectrocatalysts were systematically characterized by FTIR, XPS, SEM, TEM, UV-vis and XRD. The characterization results show that FeOOH/P:BiVO₄/rGO consisted of spherical agglomerates comprising a large number of P:BiVO₄ nanoparticles with an average size of approximately 10 nm. FeOOH nanoparticles were successfully loaded onto the surface of P:BiVO₄ nanoparticles, and rGO layers with a thickness of approximately 4 nm were coated onto the P:BiVO₄ particles. The enhanced photoelectrochemical properties were observed using linear sweep voltammetry. The mechanism underlying the observed photoelectrocatalytic activity enhancement was determined using Mott-Schottky analysis and electrochemical impedance spectroscopy. The photocurrent density of FeOOH/P:BiVO₄/rGO in a Na₂SO₄ solution with 2,4-dichlorophenol (2,4-DCP) at 0.6 V_Ag/AgCl is approximately 100 times higher than that of P:BiVO₄; the onset potentials of FeOOH/P:BiVO₄/rGO (0.008 V_Ag/AgCl) is 5 times lower than that of P:BiVO₄ (0.043 V_Ag/AgCl). It is suggested that FeOOH/P:BiVO₄/rGO obtains the highest photoelectrocatalytic performance for 2,4-DCP degradation. The proposed mechanism is that the synergistic effect between FeOOH and rGO can alleviate two main limitations of P:BiVO₄: suppression on the bulk recombination and interfacial recombination formed at the P:BiVO₄-FeOOH junction and effective charge transfer at the semiconductor/electrolyte interface.

中文翻译：

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FeOOH和rGO耦合增强了磷酸盐掺杂BiVO4光电电极的光电化学性能

钒酸铋是一种很有前途的光阳极，它对水氧化和有机污染物的光电化学降解具有一系列固有的局限性。通过用磷酸盐（P：BiVO ₄）掺杂BiVO ₄晶格，在P：BiVO ₄纳米粒子上光沉积FeOOH纳米粒子并减少接枝，成功开发了电荷转移阻力很小的FeOOH / P：BiVO ₄ / rGO复合材料。氧化石墨烯（rGO）到P：BiVO ₄的表面上， 以该顺序。该复合光电极有效地抑制了电子-空穴复合以及在半导体/电解质界面处的电荷转移，从而显着提高了光电化学性能。通过FTIR，XPS，SEM，TEM，UV-vis和XRD对光催化剂进行了系统表征。表征结果表明，FeOOH / P：BiVO ₄ / rGO由球形团聚体组成，球形团聚体包含大量P：BiVO ₄纳米粒子，平均粒径约为10 nm。FeOOH纳米颗粒成功地加载到P：BiVO ₄纳米颗粒的表面上，并且将厚度约为4 nm的rGO层涂覆到P：BiVO _4上粒子。使用线性扫描伏安法观察到增强的光电化学性质。使用Mott-Schottky分析和电化学阻抗谱确定了观察到的光电催化活性增强的基础机理。在带有2,4-二氯苯酚（2,4-DCP）的Na ₂ SO ₄溶液中，FeOOH / P：BiVO ₄ / rGO在0.6 V _{Ag / AgCl}处的光电流密度比P：BiVO ₄高约100倍; FeOOH / P：BiVO ₄ / rGO（0.008 V _{Ag / AgCl}）的起始电位比P：BiVO ₄（0.043 V _{Ag / AgCl}）的起始电位低5倍。建议使用FeOOH / P：BiVO ₄/ rGO对2,4-DCP降解具有最高的光电催化性能。提出的机制是FeOOH和rGO之间的协同效应可以缓解P：BiVO _4的两个主要局限性：抑制P：BiVO ₄ -FeOOH结处的本体重组和界面重组以及在半导体/电解质上有效的电荷转移界面。