Enhanced H2 evolution based on ultrasound-assisted piezo-catalysis of modified MoS2†
Abstract
Piezo-catalysis of H2 evolution from water has been realized from MoS2 nanosheets with few-layers using mechanical energy. The internal electric field along the [001] direction induced by ultrasonic compression has been proposed as the intrinsic driving force for the separation and transport of carriers in MoS2. In addition, we showed that the edge of MoS2 nanosheets provided active sites, which were beneficial for the HER (hydrogen evolution reaction) after acidification treatment; thus, the piezo-catalysis of H2 evolution reached 70 μmol g−1 h−1. Furthermore, surface-modified MoS2 using glutathione (GSH) achieved a high H2 evolution of ∼1250 μmol g−1 h−1. The decorated ligands of GSH played a key role in promoting the separation of carriers. Thus, we suggest that surface treatments, which bring enhanced piezo-electricity and catalytic coupling, lead to efficient carrier separation and a high possibility of energy transformation from mechanical energy to chemical energy.