Improvement of piezocatalytic performance of Na0.5Bi0.5TiO3 perovskite using K doping for efficient Rhodamine B degradation

TL;DR

This study enhances the piezocatalytic degradation of Rhodamine B dye using K-doped Na0.5Bi0.5TiO3, achieving significantly improved efficiency through structural and compositional optimization.

Contribution

It introduces potassium doping in Na0.5Bi0.5TiO3 to significantly improve piezocatalytic performance for dye degradation, highlighting the role of MPB and structural factors.

Findings

8 times higher rate constant than undoped catalyst

Complete degradation in 90 minutes under ultrasonic vibration

Good reusability and mineralization observed

Abstract

Piezocatalysis, based on the piezoelectric properties of catalysts, breaks down the barrier between mechanical energy and chemical energy. It describes the use of charges induced by piezoelectricity to assist typical chemical processes while harvesting various forms of mechanical green energy. The performance of piezocatalysis is predominantly governed by the piezoelectric properties of materials. The main aim of this work is to evaluate and analyze the potential of potassium doped sodium bismuth titanate Na0.5-xKxBi0.5TiO3 abbreviated as NKxBT (0, 0.15, 0.20, and 0.25), as a piezocatalyst in the degradation of the organic dye Rhodamine B RhB under ultrasonic vibration. The synthesis of NKxBT nanopowders was conducted using the sol-gel autocombustion method. Coupled structural analysis reveals the presence of an intermediate Morphotropic Phase Boundary (MPB, where two phases coexist) in the optimal NK15BT composition. The piezocatalytic degradation results showed a total piezo-degradation in only 90 min and a rate constant 8 times higher than the undoped NK0BT. The enhanced piezocatalytic activity results from a synergistic effect of MPB presence, reduced particle size, optimal bandgap and high lattice strain. The NK15BT sample also demonstrated good reusability and good mineralization.