Interfacial engineering of Bi2MoO6-BaTiO3 Type-I heterojunction promotes cocatalyst-free piezocatalytic H2 production

Abstract

Single component semiconductor materials with piezoelectric response can promote the activation of hydrogen ions (H+) and the generation of hydrogen (H2) under the action of mechanical force, but the high recombination rate of carriers is the major obstacle to strengthen piezocatalytic efficiency. Here, a groundbreaking Bi2MoO6-BaTiO3 (BMO-BTO) Type-I heterojunction piezocatalyst is successfully fabricated through a solvothermal strategy, and applied for cocatalysts-free piezocatalytic H2 production reaction. Under ultrasonic vibration, the H2 production rate of BMO-0.1BTO heterojunction can reach up to nearly 152.57 µmol/g/h, which is approximately 9.33 and 4.47 times with respect to that of pristine BMO (16.36 µmol/g/h) and BTO (34.16 µmol/g/h) alone, respectively. Furthermore, BMO is also combined with other commonly used piezocatalysts to construct heterojunctions, and analogous marvelous piezocatalytic H2 production performance was attained. The enhanced piezocatalytic H2 production performance can be credited to the established built-in electric field (BIEF) in heterojunction extraordinarily suppressed the recombination rates of piezocarriers, rather than an increase in piezoelectricity, which is emphatically verified through a series of physics and chemical characterizations. This study presents an innovative paradigm for fabricating BMO-based heterojunction piezocatalyst to efficiently convert mechanical energy into chemical energy.