Enhancement of the visible light photocatalytic activity of heterojunction In2O3/BiVO4 composites

Abstract

Novel In 2 O 3 /BiVO 4 heterojunction composite photocatalysts with tunable In 2 O 3 content were prepared using a mild hydrothermal method. The structure, composition, and optical properties of the In 2 O 3 /BiVO 4 composites were determined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-Vis diffuse reflectance spectroscopy, Brunauer-Emmett-Teller surface analysis, and X-ray photoelectron spectroscopy. Furthermore, photocatalytic activities of the as-prepared composites were investigated by studying the degradation of methylene blue (MB) solutions under simulated visible light irradiation (k [ 420 nm). It was found that the 50 % proportion of In 2 O 3 in the In 2 O 3 /BiVO 4 composite exhibited the highest photocatalytic performance, leading to 91 % decomposition of MB within 240 min of irradiation.

Thin-Layer Indium Oxide and Cobalt Oxyhydroxide Cobalt-Modified BiVO4 Photoanode for Solar-Assisted Water Electrolysis

“…As a promising water oxidation photocatalyst BiVO 4 possesses suitable valence band maximum (VBM) position (2.53 V vs NHE) which means a sufficient oxidative ability for oxygen evolution . Meanwhile, its conduction band minimum (CBM) lies at potential (−0.02 V vs NHE) slightly lower than that of hydrogen evolution potential (0 V vs NHE) . The band alignment renders BiVO 4 a suitable band gap for visible light absorption and relatively lower overpotential for hydrogen evolution in a photoelectrochemical cell.…”

“…14 Meanwhile, its conduction band minimum (CBM) lies at potential (−0.02 V vs NHE) slightly lower than that of hydrogen evolution potential (0 V vs NHE). 10 The band alignment renders BiVO 4 a suitable band gap for visible light absorption and relatively lower overpotential for hydrogen evolution in a photoelectrochemical cell. On the other hand, In 2 O 3 , as was reported, has a conduction band bottom at −0.62 V vs NHE and valence band maximum situating at 2.18 V vs NHE.…”

“…Through building a physical contact between two semiconductor materials with thermodynamically matched band structure, the equilibrium of charge carrier contributes to form an anisotropic field near the contacting interface which will boost the separation of electron–hole pairs and the flux of hole in the bulk of semiconductor. In light of that, In 2 O 3 possess a favorable conduction band and valence band position, which are respectively situated at −0.62 and 2.18 V versus NHE and well matched with those of BiVO 4 . , …”

BiVO4based highkmicrowave dielectric materials: a review

“…Yeom et al 85 employed Electron Paramagnetic Resonance (EPR) to confirm that Gd 3+ substitutes for Bi 3+ in monoclinic BiVO4 but no further data on the ceramics was reported. Yin et al 86 studied the composite of In2O3-BiVO4 by using a soft chemical approach with composites sintered at 500 o C. When the In/Bi ratio was less than unity, only monoclinic BiVO4 phase was detected using XRD, as shown in Fig. 14 87 for x ≤ 0.08, no secondary phases were revealed in XRD patterns but for x > 0.08 peaks of FeVO4 phase were observed.…”

Enhanced photocatalytic activity exhibited by PTh/[Fe(CN)3(NO)(bpy)]·4H2O nanocomposite fibers via a synergistic approach

“…Such factors are complementary to one another since there are systems having lower surface area are efficient photocatalysts and vice versa. 4 Large surface area leads to efficient adsorption of dye for degradation, greater interface contact between different components and easy migration of charge carriers leads to decreased electron-hole pair recombination thereby prolonged the life time of charge carriers. Interface contact is not either enough to increase photocatalytic activity if there is no charge separation, which can occur only once the system is conducting.…”