BiVO₄-Dotted WO₃ Photoanode with an Inverse Opal Underlayer for Photoelectrochemical Water Splitting

Abstract

Developing an efficient photoanode is critical for obtaining sustainable hydrogen energy by photoelectrochemical (PEC) water splitting. The performance of a photoanode is usually determined by charge separation and optical absorption efficiency, which can be enhanced by constructing a solid-state junction and applying an inverse opal (IO) structure, respectively. Following such principles, we developed a BiVO4/WO3-IO photoanode with a BiVO4/WO3 junction and an IO layer as an underlayer. Compared with a bare WO3 photoanode with an onset potential of 0.80 VRHE and a photocurrent of 0.13 mA/cm2 at 1.23 VRHE, the BiVO4/WO3-IO photoanode exhibited much better PEC performance with an onset potential of 0.46 VRHE and a photocurrent of 0.94 mA/cm2 at 1.23 VRHE. Such a successful combination of two kinds of modification provides a promising approach to effectively utilize solar energy in visible-light-responsive photoanodes.

Mo-BiVO4/Ca-BiVO4 Homojunction Nanostructure-Based Inverse Opals for Photoelectrocatalytic Pharmaceutical Degradation under Visible Light

“…PC structuring has been further exploited for the fabrication of efficient Mo-doped BiVO 4 inverse opal photoanodes relying on their meso-macropore texture, while distinctly improved PEC activity was reported for surface modified BiVO 4 PC films by Au and Ag plasmonic nanoparticles. MO inverse opals have been further exploited as photonic supports and underlayers for the deposition of nanostructured BiVO 4 layers leading to enhanced charge separation and highly efficient PEC water splitting through heterojunction formation. Although slow photon effects were not systematically explored in all cases, the enhanced activity of nanostructured BiVO 4 PCs corroborates their competence for photocatalytic applications, as recently shown by the markedly improved carrier dynamics in BiVO 4 inverse opals due to confinement effects in their nanocrystalline skeleton …”

A robust methodology for PEC performance analysis of photoanodes using machine learning and analytical data

“…[64][65][66] Although these samples were made of a heterojunction, a certain proportion of the surface is exposed with WO 3 from the previous result. 67 It is surprising that the secondly dominant descriptor, XRD_pk15_int, shown in Fig. 12, corresponds to the (015) facet of BiVO 4 ; there are no reports indicating that this facet has the photocatalytic activity.…”

P-Doped g-C3N4 Nanosheet-Modified BiVO4 Hybrid Nanostructure as an Efficient Visible Light-Driven Water Splitting Photoanode

“…Among multitudinous semiconductors, bismuth vanadate (BiVO 4 ) has been considered one of the foremost semiconductors in photocatalysis and photoelectrochemical water splitting due to its appropriate band gap (∼2.4 eV) and the position of band edges. , It must be considered that BiVO 4 has some drawbacks including poor charge separation and fast electron–hole recombination, which could restrict its photocatalytic efficiency . To overcome these shortcomings, different efforts have been conducted, such as morphological engineering, vacancy defect engineering, elemental doping, introducing cocatalysts, and combining with other semiconductors . Among these approaches, formation of a heterostructure system with different semiconductors has been suggested by many researchers as a practical method to enhance charge separation and transportation, providing a higher photocatalytic performance …”

“…10 To overcome these shortcomings, different efforts have been conducted, such as morphological engineering, 11 vacancy defect engineering, 12 elemental doping, 13 introducing cocatalysts, 14 and combining with other semiconductors. 15 Among these approaches, formation of a heterostructure system with different semiconductors has been suggested by many researchers as a practical method to enhance charge separation and transportation, providing a higher photocatalytic performance. 16 T h i s c o n t e n t i s Carbonaceous semiconductors, i.e., graphene oxide (GO), carbon nanotubes (CNTs), and graphitic carbon nitride (GCN), are promising materials due to their high conductivity, mechanical and chemical stability, abundance in nature, and biocompatibility.…”