Oxygen-incorporated MoS₂ catalyst for remarkable enhancing piezocatalytic H₂ evolution and degradation of organic pollutant

A highly efficient piezocatalyst of oxygen-incorporated MoS₂ (O-MoS₂) was designed and successfully synthesized via facile modulation of hydrothermal process temperature method. Remarkably, a superior piezocatalytic H₂ evolution rate of 46.1 μmol·g⁻¹·h⁻¹ in pure water and 921.0 μmol·g⁻¹·h⁻¹ in methanol solution is obtained on optimal O-MoS₂-180 (with a hydrothermal process temperature of 180 °C), outperforming pristine MoS₂ and most of the reported other catalysts. Moreover, piezocatalytic activity of O-MoS₂ toward the degradation of organic pollutants depends on hydrothermal temperatures. The suitable temperature of O-MoS₂-180 presents dramatically excellent piezocatalytic capacity compared with the pristine MoS₂ for degradation of methylene blue (MB) dye. The reaction rate constant of O-MoS₂-180 reaches to 54.6 × 10⁻³ min⁻¹, which is nearly 18 and 4-folds in contrast with pristine MoS₂ and O-MoS₂-140 (with a hydrothermal process temperature of 140 °C), respectively. Simultaneously, it also manifests that O-MoS₂-180 endows relatively high degradation efficiency (84.6% within 30 min) and excellent stability. Moreover, it is also demonstrated that optimal O-MoS₂ can dramatically promote charge carriers transport and separation. Furthermore, our theoretical calculation results suggest that the oxygen-incorporated can modulate the surface electronic state, enhance active sites as well as optimize the hydrogen adsorption Gibbs free energy of MoS₂, thus extremely boosting piezocatalytic efficiency. Ultimately, an innovative piezocatalytic mechanism is proposed to reveal and expound the relationship between piezocatalytic property and oxygen-incorporated role.