Enhanced photo activity by hole concentration on CdS surface

Abstract Confirmed by the test, the amount of the sulfur defect in CdS is simply controlled by varying the amount of acid added. The concentration of the surface hole has been influenced by the increasing of the sulfur defect. The visible light activity (λ > 420 nm) of 275-CdS (275: adding 275 μL HNO3) is about 1.39 and 1.35 times as high as that of CdS and 400-CdS (400: adding 400 μL HNO3) , respectively. The increased concentration of the hole on catalyst surface is the main reason for the improved degradation performance.