[20a-P02-1~17] 1.4 Energy conversion, storage, resources and environment

▲ [20a-P02-6] Improvement of Photoelectrochemical Water Splitting by Bridging Strategy of P-N Heterojunction Using Co-catalyst

〇(D)Lingga Ghufira Oktariza¹, Namiki Uezono¹, Jiaqi Liu¹, Shukur Gofurov¹, Sachin A. Pawar¹, Muhammad Monirul Islam¹, Shigeru Ikeda², Takeaki Sakurai¹ (1.University of Tsukuba, 2.Konan University)

Keywords:semiconductor, photocatalysis

Constructing the suitable heterojunction with a built-in electric field at the interface facilitates an effective approach to achieve the great charge carrier separation and transportation for photoelectrochemical (PEC) water splitting [1]. Bismuth Vanadate (BiVO₄) is n-type semiconductor and sustainability-inspired photoanode material for PEC with a suitable bandgap for visible light absorption. Cuprous Oxide (Cu₂O), p-type semiconductor, has suitable band positions to match with BiVO₄ making it an ideal heterojunction for photoanode PEC water splitting. Another perspective for stimulating the charge kinetics between p and n type semiconductor interface is to integrate NiFe (Nickel-Iron) nanosheets on the BiVO₄ surface as co-catalyst. Here, we introduce the NiFe co-catalyst bridging the BiVO₄ and Cu₂O to boost the PEC performance for oxygen evolution reaction photoanode. BiVO₄ was deposited on the conductive glass substrates by Radio Frequency (RF) sputtering machine with the appropriate growth condition. The deposition process was done by establishing the substrate temperature, pressure, RF power, and flow rate of argon and oxygen. Thereafter NiFe was deposited on the BiVO₄ thin film by hydrothermal method. The final stage is to deposit Cu₂O on the BiVO₄/NiFe layer using RF sputtering machine. The bridging strategy of p-n heterojunction using NiFe co-catalyst has significantly reduced the onset potential, and enhanced charge separation of the BiVO₄/Cu₂O based photoanode, culminating in achieving a photocurrent density of 0.68 mA/cm² at 1.23 V vs. the reversible hydrogen electrode. This work provides a promising strategy for optimizing oxygen evolution reaction catalysts to develop efficient PEC water splitting devices.