In situ fabrication of WO3/CuWO4/CuO heterojunction photoanode for boosted interfacial charge transfer and enhanced photoelectrochemical water splitting

Constructing high-quality interfaces is critical for improving carrier separation efficiency in heterojunctions. Herein, the WO3/CuWO4/CuO ternary heterojunction films was constructed on FTO substrates for the first time through in-situ technique as an effective photoanode for photoelectrochemical hydrogen production. The CuO nanoparticles loaded WO3 nanorod with buffer layer CuWO4 significantly increased the absorption capability of visible light, accelerate charge separation and enhanced photoelectrochemical performance. The photocurrent density of WO3/CuWO4/CuO heterojunction photoelectrode achieved 2.24 mA∙cm-2 at 1.23 V vs. RHE, which is nearly 5.6 times higher than bare WO3 photoanode. In addition, the onset potential of WO3/CuWO4/CuO heterojunction shifted negatively by 110 mV compared to WO3. This work indicates that designing high-quality interface heterojunction photoanodes via an atomic shared is an effective strategy for achieve effective photoelectrochemical performance.