Precise regulation of Ultra-thin platinum decorated Gold/Graphite carbon nitride photocatalysts by atomic layer deposition for efficient degradation of Rhodamine B under simulated sunlight

Abstract

Atomic Layer Deposition (ALD) precise controlling ultra-thin platinum (Pt) modified Graphite carbon nitride (g-C3N4) photocatalysts, which had been doped with gold nanoparticles (Au NPs) by photodeposition, were successfully synthesized. The experimental results showed that precise regulation of platinum decorated C3N4-Au(C3N4-Au/nPt (n is the number of Pt ALD cycles, 1 Å per cycle)) exhibited excellent photocatalytic degradation ability for Rhodamine B (RhB). Under simulated sunlight irradiation, the degradation rate of 10 mg/L RhB(100 mL) by 1.5 mg C3N4-Au/10Pt catalysts was 95.8% within 60 min that is much better than other photocatalysts for the degradation of RhB. The efficient degradation mechanism of RhB by C3N4-Au/10Pt photocatalysts was studied and the experiments demonstrated the ·O2– as main active species played an important role in the photocatalytic process. Local surface plasmon resonance (LSPR) of Au NPs and Schottky barrier between Pt clusters and g-C3N4 may be the reasons for enhanced C3N4-Au/10Pt photocatalytic performances. Furthermore, the successive catalytic cycles revealed the excellent stability of C3N4-Au/10Pt photocatalyst.