Conversion of both photon and mechanical energy into chemical energy using higher concentration of Al doped ZnO

Abstract

Synthesis of materials to harvest photon energy together with mechanical energy beneficial to address the current energy shortage and enhance the photocatalytic properties of the material. Bare ZnO displays poor photocatalytic properties under visible light illumination owing to higher bandgap energy. Intrinsic defect engineering of ZnO lattice by Al doping enhance the visible light harvesting ability and the better piezoelectric properties contribute additional electron in the lattice would upsurge the piezo-photocatalytic property under the visible region. Aluminum doped in ZnO lattice prepared by two-step sintering method in which the Al doped ZnO (AZO) sintered at 150 °C for one hour and followed by 500 °C for two hours. The enhanced piezo-photocatalytic properties verified based on the piezo-photocatalytic degradation of Methylene blue dye under visible light together with mechanical vibration. The enhanced piezo-photocatalytic activity attributed to enhanced visible light harvesting via defects in the lattice, freely existence of electron in the AZO lattice, enhanced surface area and zinc/oxygen vacancies in the lattice. The AZO shows better piezo-photocatalytic properties and almost 53.7% enhanced piezo-photocatalytic efficiency than the bare ZnO under the visible light illumination. This work highlights the attractive piezo-photocatalytic properties of 10% Al-doped ZnO (AZO-10) via strong coupling of visible light harvesting and piezoelectricity to convert both photon and mechanical energy into chemical energy.