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

Single component semiconductor materials with piezoelectric response can promote the activation of hydrogen ions (H + ) and the generation of hydrogen (H 2 ) under the action of mechanical force, but the high recombination rate of carriers is the major obstacle to strengthen piezocatalytic efficiency. Here, a groundbreaking Bi 2 MoO 6 -BaTiO 3 (BMO-BTO) Type-I heterojunction piezocatalyst is successfully fabricated through a solvothermal strategy, and applied for cocatalysts-free piezocatalytic H 2 production reaction. Under ultrasonic vibration, the H 2 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 H 2 production performance was attained. The enhanced piezocatalytic H 2 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. Bi 2 MoO 6 -BaTiO 3 (BMO-BTO) Type-I heterojunction piezocatalyst is successfully fabricated and applied for cocatalysts-free piezocatalytic H 2 production reaction. The enhanced piezocatalytic H 2 performance can be attributed to the established built-in electric field (BIEF) in heterojunction remarkably reduced the recombination rates of carriers, rather than an increase in piezoelectricity. • Highly efficient piezocatalysts of BMO-BTO Type-I heterojunctions were rationally designed. • BMO-BTO Type-I heterojunctions owned excellent piezocatalytic H 2 production activity and stability. • An innovative piezocatalytic mechanism of BMO-BTO Type-I heterojunctions was reasonably elucidated. • The enhanced H 2 production rate can be attributed to the new BIEF, rather than an increase in material piezoelectricity.