Two-Dimensional MoS2/g-C3N4 S-scheme heterojunction with Piezo–Photocatalytic synergy for enhanced hydrogen production

Piezoelectric photocatalysis is emerging as a promising approach for green environmental protection. Herein, a molybdenum disulfide/graphitic carbon nitride S-scheme heterojunction catalyst achieved a Rhodamine B degradation rate exceeding 99 % within 30 min under the synergistic effects of light and ultrasound, along with a hydrogen (H 2 ) production rate of 16.2 mmol g −1 h −1 . The synergy of ultrasound and light improved catalytic efficiency by approximately 45 % compared with light alone. Experimental characterizations, including Kelvin probe force microscopy, in situ X-ray photoelectron spectroscopy, and density functional theory calculations, confirmed the presence of dual built-in electric fields arising from band alignment and strain-induced polarization. These fields facilitated efficient electron–hole separation, thereby greatly enhancing the overall piezoelectric photocatalytic performance and resulting in efficient use of mechanical and solar energy for H 2 production and pollutant decomposition.