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

Abstract

Fabrication of high-performance tandem cell for solar-assisted water cleavage requires an efficient photoanode with excellent bulk charge separation and surface injection. In light of that, we developed a hybrid photoanode using visible light absorber as main scaffold, a thin layer In 2 O 3 middle layer to enhance charge separation in bulk and finally an active CoOOH catalyst as outer decoration for better surface charge injection. Bulk separation was mainly augmented by In 2 O 3 addition, while the addition of CoOOH largely advanced photocurrent onset and elevated injection efficiency. The resultant photoanode delivered a high current density at low applied bias, showing promising prospect for incorporation into tandem cell for solar-assisted water electrolysis.

Efficient Water Splitting Cascade Photoanodes with Ligand‐Engineered MnO Cocatalysts

“…The BF 4 ‐treated MnO/BiVO 4 /WO 3 anode achieved 6.25 mA cm −2 at the 1.23 V versus RHE. We emphasize that the photocurrent of BF 4 ‐treated MnO attached to the BiVO 4 /WO 3 anode is the highest of the previously reported BiVO 4 ‐based photoanodes with hole scavenger for solar water splitting, as shown in Table S2 and Figure S4 (Supporting Information) . Otherwise, Ca–EDTA‐treated MnO NPs/BiVO 4 /WO 3 recorded the lowest photocurrent density of about 2.5 mA cm −2 .…”

“…Therefore, most of the previously reported results related to BiVO 4 ‐based photoanodes were measured in sulfite oxidation condition to show photo‐electrochemical properties of BiVO 4 ‐based electrodes independently of its poor water oxidation kinetics, as shown in Table S2 (Supporting Information). The photo‐electrochemical current densities of the BiVO 4 ‐based photoanodes were plotted as a function of potential versus RHE. Thus, we measured PEC properties of BiVO 4 ‐based anodes under sulfite oxidation to figure out the effect of ligand engineering.…”

Dual Modification of a BiVO4 Photoanode for Enhanced Photoelectrochemical Performance

“…The ABPE obtained from Figure B suggests that the optimum composite of the photoanode (CoPi/NiMoO 4 /BiVO 4 ) reaches a maximum efficiency of 1.18 % at 0.86 V, and for NiMoO 4 /BiVO 4 it is 0.66 % at 0.86 V; both of which exceed that of BiVO 4 (0.13 % at 0.94 V).In agreement with the photocurrent density and light conversion efficiency, the IPCE results in Figure C clearly reveal the positive effects of NiMoO 4 and CoPi. The NiMoO 4 /BiVO 4 composite photoanode shows a 30 % increase, compared with that of bare BiVO 4 at λ =430 nm; in contrast, the spectral distribution remains nearly the same as that of BiVO 4 , which indicates that NiMoO 4 shows little photo‐to‐current efficiency, although it has a slightly broader absorption range in the UV/Vis diffuse reflection spectrum . Thus, the much higher value of NiMoO 4 /BiVO 4 may derive from a significant enhancement of the charge separation efficiency, on account of heterojunction formation .…”

Rational Design and Construction of Cocatalysts for Semiconductor‐Based Photo‐Electrochemical Oxygen Evolution: A Comprehensive Review

“…Moreover, Co‐based (oxy)hydroxides were also recognized as the robust and promising cocatalysts to lower onset potential and favor injection of charge carriers . Many groups have been working on it . A Co(OH) x cocatalyst could help Ta 3 N 5 photoanode have a significantly improved photocurrent of 5.5 mA cm −2 at 1.23 V RHE , which is one of the highest values among all currently available Ta 3 N 5 photoanodes .…”