Boron Carbon Nitride Semiconductors Decorated with CdS Nanoparticles for Photocatalytic Reduction of CO 2

Ternary boron carbon nitride (BCN) semiconductors have been developed as emerging metal-free photocatalysts for visible-light reduction of CO 2, but the achieved efficiency is still not satisfying. Herein, we report that the CO 2 photoreduction performance of a bulk BCN semiconductor can be substantially improved by surface engineering with CdS nanoparticles. The CdS/BCN photocatalysts are characterized completely by diverse tests (e.g., XRD, FTIR, XPS, DRS, SEM, TEM, N 2 sorption, PL, and transient photocurrent spectroscopy). Performance of the CdS/BCN heterostructures is evaluated by reductive CO 2 conversion reactions with visible light under benign reaction conditions. Compared with bare BCN material, the optimized CdS/BCN photocatalyst exhibits a 10-fold-enhanced CO 2 reduction activity and high stability, delivering a considerable CO production rate of 12.5 μmol h –1 (250 μmol h –1 g –1 ) with triethanolamine (TEOA) as the reducing agent. The reinforced photocatalytic CO 2 reduction activity is mainly assigned to the obviously improved visible-light harvesting and the greatly accelerated separation/transport kinetics of light-triggered electron–hole pairs. Furthermore, a possible visible-light-induced CO 2 reduction mechanism is proposed on the basis of photocatalytic and photo(electro)chemical results.