Visible-light-induced photocatalytic performances of ZnO–CuO nanocomposites for degradation of 2,4-dichlorophenol

Enhanced visible photocatalytic activity of Fe‐Cu‐ZnO/graphene oxide photocatalysts for the degradation of organic dyes

“…ZnO is an amphoteric oxide, which can form the amphoteric compounds with water in solution. Hence, that phenomenon can be caused by changing the electrostatic attraction or repulsion between the dye molecules and the catalyst . In an acidic solution, a positively charged particle on the surface of ZnO promotes the migration of photogenerated electrons to the catalyst surface, which could react with the adsorbed O 2 to produce • O 2 – , thus inhibiting the recombination of the photogenerated electron‐hole pairs.…”

“…Simultaneously, some intermediates generated in the photodegradation process can be adsorbed on the catalyst surface resulting in deactivation of active sites on the photocatalyst. As a result, the degradation rate slows down and tends to be stable . Therefore, the optimal reaction time for the photocatalysis in this experiment is 90 min.…”

“…Hence, that phenomenon can be caused by changing the electrostatic attraction or repulsion between the dye molecules and the catalyst. [5,35] In an acidic solution, a positively charged particle on the surface of ZnO promotes the migration of photogenerated electrons to the catalyst surface, which could react with the adsorbed O 2 to produce • O 2 -, thus inhibiting the recombination of the photogenerated electron-hole pairs. At the same time, because dark green dye is an anionic dye, its surface is in a negatively charged state after ionization in the lower pH.…”

“…In recent years, semiconductor heterogeneous photocatalysis has received wide attention and been developed due to its important application for the degradation of organic contaminants from industrial effluents by effective utilization of solar energy . Amongst the various oxide‐based semiconductor photocatalysts applied, TiO 2 and ZnO are the most frequently used photocatalysts .…”

“…I n recent years, semiconductor heterogeneous photocatalysis has received wide attention and been developed due to its important application for the degradation of organic contaminants from industrial effluents by effective utilization of solar energy. [1][2][3][4][5][6] Amongst the various oxide-based semiconductor photocatalysts applied, TiO 2 and ZnO are the most frequently used photocatalysts. [3,[7][8][9] Recently, some studies have shown that ZnO, with a high photosensitivity, non-expensive cost, and excellent chemical stability has better photocatalytic activity in degradation of some organic pollutions than that of TiO 2 .…”