Efficient piezo-assisted near-infrared-light-driven Cr(VI) reduction over Bi₂S₃ nanowires transformed from ultrathin Bi₂WO₆ nanosheets

The utilization of piezo-photocatalytic technology for environmental remediation under full spectrum solar light is promising but still challenging. Herein, one-dimensional Bi₂S₃ nanowires, which can utilize both mechanical energy and near-infrared (NIR) light to remove hexavalent chromium (Cr (VI)) efficiently, were synthesized by a restrained growth method. The reaction rate constants of Cr (VI) reduction in piezo-photocatalytic process under NIR (800–2500 nm) reached 0.334 min⁻¹, which were 3.2 and 12.4 times as that of single piezo and photocatalytic process. The formation of polarized electric fields and one-dimensional structure allow ultrafast separation of charge carriers, thereby promoting the catalytic activity. Furthermore, due to the strong penetrability of NIR light, the piezo-photocatalysis performance in turbid solutions under NIR light (0.188 min⁻¹) was even comparable to that under visible light (0.186 min⁻¹). This study provides a new concept on the development of piezo-photocatalytic technology for environmental remediation by utilization of NIR light and natural mechanical energy.