Photoelectrochemical Performance Of Multicomponent Bismuth Vanadate Semiconductor Photoelectrode

The amount of fossil energy storage is decreasing day by day,and a series of environmental problems arise when it is used.Human beings need to find clean energy which can replace fossil energy to meet the needs of social development.Solar energy is easy to obtain and renewable.Using solar energy to obtain energy through photosynthesis is an effective way to solve the energy crisis.Building photochemical cells is a viable method for artificial photosynthesis,splitting water to produce H₂ or reducing CO₂ to produce carbon-based fuel molecules.However,there are a series of problems that need to be solved,such as recombination of photogenerated electrons and holes and poor kinetics of water decomposition.Based on the above reasons,in this paper,gold nanoparticles and metal-organic Frameworks（MOFs）were assembled and loaded on the surface of Bi VO₄ by impregnation method,and Bi VO₄/Au+MOF multigroup spectroscopic anodes were constructed.The structure was characterized by scanning,transmission electron microscopy,XPS and other means.It is proved that the multiple groups of spectroanodes are successfully prepared.When the performance of the electrode is tested,it is found that the photocurrent density of Bi VO₄/Au+MOF anode can reach4.98 m A/cm~2 at the voltage of 1.23 V vs.RHE by mixing gold nanoparticles with MOF suspension and then assembling on Bi VO₄.Compared with Bi VO₄ electrode,the MOF material can effectively utilize the photogenerated holes agglomerated around gold nanoparticles.In order to enhance the stability of Bi VO₄/Au+MOF composite electrode,a layer of Ni OOH thin film was deposited by the hydrolysis of Ni²⁺between the two layers,and the Bi VO₄/Ni OOH/Au+MOF photoanode was obtained.The photocurrent density maintained at about 2.85 m A/cm~2,showing good stability.In addition,Bi VO₄/Co F₂,Bi VO₄/Ni F₂ composite photoanodes were prepared by impregnating metal fluoride as a cocatalyst on Bi VO₄.The metal fluoride modified electrode is more hydrophilic and the petal-like skeleton structure accelerates the adsorption process of oxygen-containing intermediates.The photoelectric performance of the electrode was tested,the photocurrent density of Bi VO₄/Co F₂ and Bi VO₄/Ni F₂ electrodes is 4.90 m A/cm~2 and 4.20 m A/cm~2 at the voltage of 1.23 V vs.RHE.The results are 3.2 times and 2.8 times higher than those of the unmodified Bi VO₄ electrode,respectively,which are far superior to the traditional Co Pi and Ni OOH catalyst modified electrode.