Unveiling the impact of interfacially engineered selective V2O5 nanobelt bundles with flake-like ZnO and Co–ZnO thin films for multifunctional visible-light water splitting and toxic gas sensing

Abstract

We report on novel interfacial assembly behavior of V2O5 nanobelt bundles (V2O5 NBBs) paired with flake-like ZnO (V2O5/ZnO) and Co (1.8 at.%)-ZnO (V2O5/Co–ZnO) thin films for the first time. This work accomplished highly stable visible-light-driven photoelectrochemical (PEC) water splitting and toxic NO2 gas sensing. Mainly, charge carrier acceleration ability is associated with the interfacial diffusion behavior between nanobelt and flake-like morphologies. Structural studies revealed strong network formation between predominant ZnO (002) and V2O5 (001). Because of nanobelt/flake-like intimate interaction, we fairly established the flake-like ZnO and Co–ZnO morphological features on V2O5 NBBs. Accordingly, chemical analysis of V2O5/Co–ZnO illustrated a shift in the O 1s peak position towards lower binding energy, which is ascribed to the impressive combined oxygen bonding formation at the interface of Co–ZnO and V2O5. Taking advantage of the interfacial interaction and abundant hydrophilicity (63°) of V2O5/Co–ZnO, we controllably achieved stable water splitting activity about 21.0 min. In an effort, V2O5/Co–ZnO composite outperformed the photocurrent generation with 1.45 × 10−4 A/cm2, which is 42.0 times higher than ZnO. Also, V2O5/Co–ZnO attained NO2 gas response (130.0%) at 50 ppm. Comprehensively, nanobelt/flake-like morphological integration serves as a highly stable photoanode in the PEC cell as well as a toxic gas sensor. © 2020 Elsevier B.V.