Enhanced photocatalytic performance of NH2-MIL-125(Ti)/SrTiO3 heterostructures by the piezoelectric effect of SrTiO3

Applying piezoelectric effect on modulating charge transport behavior was considered as one efficient strategy to make feasible charge separation in photocatalysts towards boosting hydrogen evolution performance. Here, with employing corona-poling treatment, SrTiO3 is converted to be a piezoelectric component in the constructed type II NH2-MIL-125(Ti)/SrTiO3 heterojunction. Since the piezoelectric field could tilt the band bending to a degree to be convenient for the charge transfer from SrTiO3 to NH2-MIL-125(Ti), it is also favorable to offer additional active sites on SrTiO3 to form dual reduction sites for the following piezo-photocatalytic reaction. Both the ameliorated surficial polarization and charge transfer trajectory in NH2-MIL-125(Ti)/SrTiO3 type II heterojunction are devoted to the boosted hydrogen production rate for NH2-MIL-125(Ti)/SrTiO3-0.1 (NM/STO-0.1), that is up to 1562.3 μmol h−1 g−1, 1.79 times higher than that of unpolarized NM/STO-0.1 (871.6 μmol h−1 g−1) and 2.35 times higher than that of NH2-MIL-125(Ti) (663.8 μmol h−1 g−1), respectively. This research reported initially the assistant of SrTiO3 with piezoelectric feature for enhanced performance photocatalytic hydrogen evolution, which could be one prominent strategy to achieve the reasonable design of efficient photocatalytic system.