Interfacial band alignment and photoelectrochemical properties of all-sputtered BiVO₄/FeNiO_x and BiVO₄/FeMnO_x p–n heterojunctions

Abstract

BiVO4 is a well-known n-type semiconductor with great potential for photoelectrochemical (PEC) conversion of solar energy into chemical fuels. Nevertheless, photocurrent densities achieved for bare BiVO4 photoanodes are still far...

Triggering Synergy between p-Type Sputter-Deposited FeMnOx or FeNiOx and W-Doped BiVO4 for Enhanced Oxygen Evolution

“…A similar trend was observed for the V 2p and O 1s peaks, which shifted to lower binding energies (Figure b,c). The shift is probably due to the upward band bending effect . FeMnOx and FeNiOx cocatalysts are p-type semiconductors and BiVO4 is an n-type semiconductor, thereby forming a p–n junction .…”

“…22 Ptype FeMnO x and FeNiO x bimetallic oxides combined with ntype BiVO 4 form a p−n heterojunction which has shown significant enhancement in photocatalytic activity. 23 The bimetallic oxide cocatalysts are attached to the photocatalysts, which further improves the charge separation and local catalytic rate of the photocatalysts, varies the charge densities of the photocatalysts, and forms a built-in electric field. 24,25 Chemical routes to deposit cocatalysts on the surface of BiVO 4 are promising; however, uniform and site-selective deposition is challenging.…”

“…MnO x cocatalysts were deposited on the BiVO 4 , which has shown a tremendous increase in the photocatalytic activity by improving a surface photovoltage from 20 to 75 mV, as MnO x deposition promotes charge separation due to the formation of built-in electric . P-type FeMnO x and FeNiO x bimetallic oxides combined with n-type BiVO 4 form a p–n heterojunction which has shown significant enhancement in photocatalytic activity . The bimetallic oxide cocatalysts are attached to the photocatalysts, which further improves the charge separation and local catalytic rate of the photocatalysts, varies the charge densities of the photocatalysts, and forms a built-in electric field. , Chemical routes to deposit cocatalysts on the surface of BiVO 4 are promising; however, uniform and site-selective deposition is challenging .…”

“…The shift is probably due to the upward band bending effect. 23 FeMnOx and FeNiOx cocatalysts are p-type semiconductors and BiVO4 is an n-type semiconductor, thereby forming a p−n junction. 44 This junction induces an interfacial electric field that can help in the transfer and separation of photogenerated charge carriers.…”

“…52,60 The observed flat band is slightly different than the previously reported value. 23 The slight change in this value is attributed to the film thickness as compared with 30−120 s deposition time; here, we deposited the cocatalyst for 10 min. Figure 6b,c displays the MS curves for the pure FeNiO x and FeMnO x films.…”