Optimization of z-scheme Bi0.5Na0.5TiO3/RGO-Co3O4 composite catalyst for water splitting reaction through piezo-photocatalysis

초록

Utilizing strain-induced polarization to amplify the performance of photo-catalytic water-splitting systems has garnered significant attention in view of clean H2 evolution with no environmental footprint. However, achieving efficient charge separation, high underwater suspension efficiency, and sustained cyclic stability remains a persistent challenge. In this study, we employed a classic low-temperature ball milling technique to synthesize rhombohedral bismuth sodium titanate phase B0.5Na0.5TiO3 as a matrix material. One-step superimposed reduced graphene oxide with cobalt oxide loading RGO-Co3O4 is used as reinforcement. The cobalt oxide (Co3O4) is expected to speed up classically slow OER reaction. The addition of reinforcement lowers the band gap of our material and makes it more visible light active to optimize full spectrum absorption. We report a 14.79% increase in H2 evolution with the addition of reinforcement and optimal H2 evolution was achieved with 5% RGO-Co3O4 (517 mu mol/g-h). After the introduction of simultaneous photo and piezoelectric potential by using an ultrasonicator, H2 evolution is much enhanced 109 mu mol/g-h surpassing piezo catalysis 66 mu mol/g-h and photo catalysis 64 mu mol/g-h. Herein, we also explore renewable alternatives using manure and seawater revealing improved H2 evolution that is 1.8% and 50.4% respectively. Additionally, the piezo-photo catalyst demonstrates remarkable performance without a sacrificial agent further highlighting its exceptional potential. Moreover, we also uncover the role of Co3O4 as a co-catalyst and RGO as a promoter in direct and indirect zschemes for water splitting. This work provides insight into harnessing and designing ingenious composites for efficient and stable piezo-photo catalysts for efficient and stable water-splitting systems.

키워드