Harvesting Vibration Energy to Produce Hydrogen Peroxide with Bi<sub>3</sub>TiNbO<sub>9</sub> Nanosheets through a Water Oxidation Dominated Dual-Channel Pathway
Yongfei Cui, Fenghui Wang, Panpan Yuan, Wei Liu, Biyun Fang, Zhuo Wang, Yongping Pu
Abstract
Developing green, efficient, and sustainable techniques to synthesize hydrogen peroxide has always been the challenge faced by researchers. The rising-star piezocatalysis has been demonstrated to be capable of drive redox reactions based on the piezoelectric effect and therefore may provide novel solutions for H 2 O 2 production through mechanical energy conversion. Herein, the bismuth layered compound Bi 3 TiNbO 9 (BTNO) was utilized to produce H 2 O 2 by harvesting ultrasound vibration in a pure water system for the first time. A yield rate of 407.05 μmol·g –1 ·h –1 was achieved under ultrasonic conditions (40 kHz, 50 W) without any cocatalysts and scavengers, surpassing the majority of the reported piezocatalysts with similar mechanisms. Furthermore, a satisfied circulation and long-term running stability of piezocatalyst BTNO were proved, and the accumulated concentration of H 2 O 2 could reach 1127 μM after 5 h of reaction. The satisfied piezoelectric response of BTNO was demonstrated by piezoresponse force microscopy (PFM), electrochemical characterization, and piezodeposition experiments. On the basis of band structure analysis, the possible pathway of generating hydrogen peroxide by piezocatalysis with BTNO was proposed according to the radical-trapping and atmosphere control experiment results. It was found that both the water oxidation reaction (WOR) and oxygen reduction reaction (ORR) contributed to the yield of H 2 O 2, but direct WOR plays an absolute dominant role. In addition, Ar sparging was verified to be able to efficiently enhance the generation of H 2 O 2 due to the enlarged cavitation effect, and piezocatalysis of BTNO was found to be superior to its photocatalysis in synthesizing H 2 O 2 . It is hoped that this work can provide deep insights into piezocatalysis for H 2 O 2 generation and offer clues for the green, sustainable synthesis of hydrogen peroxide.