Zhao Mo

Synthesis of g-C3N4 at different temperatures for superior visible/UV photocatalytic performance and photoelectrochemical sensing of MB solution

In this paper, a simple preparation method was utilized to study for the optimum calcination temperature of graphitic carbon nitride (g-C3N4). The g-C3N4 prepared at different temperatures were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS) and so on. The results demonstrated that g-C3N4 could not be formed fully until the calcination temperature was higher than 500 °C. From DRS and photoluminescence (PL) spectrum, a red shift of absorption peaks with increasing calcination temperatures was found. This could enhance the visible light absorption, and then the photocatalytic activity would be improved. The photocatalytic activity was evaluated via the photodegradation of methylene blue (MB) and 4-chlorophenol (4-CP), respectively. Moreover, due to the gradual decrement trend of photocurrent intensity with addition of MB, g-C3N4 prepared at 650 °C could be used as a photoelectrochemical sensor to detect the existence of MB and estimate the concentration of MB. Hence g-C3N4 will become a promising candidate for photoelectrochemical applications.

A silver on 2D white-C3N4 support photocatalyst for mechanistic insights: synergetic utilization of plasmonic effect for solar hydrogen evolution

A photocatalyst integrating silver surface plasmon effect into two-dimensional g-C3N4 nanosheets (2D white-C3N4) was prepared successfully. The crystal structure, chemical states, morphology and photocatalytic performance of the prepared samples were researched by the comprehensive characterization methods. The photocatalytic activities of Ag/2D white g-C3N4 composites were dramatically enhanced under visible light irradiation. When Ag content was optimized, 2% Ag/white g-C3N4 exhibited the best photocatalytic activity. The electrochemical investigation verified the role of the hot electrons from the plasmonic Ag in the photocatalytic reaction. The plasmonic hot electron injection and advantages of 2D ultrathin structure improved the density of the electrons with reducibility and led to more efficient separation of photogenerated electron and hole pairs. The photocatalytic mechanism was also researched in detail via ESR analysis.

WO3 nanorod photocatalysts decorated with few-layer g-C3N4 nanosheets: controllable synthesis and photocatalytic mechanism research

Novel WO3 nanorod (WO3 NRs) photocatalysts decorated with few-layer g-C3N4 nanosheets (flg-C3N4) have been synthesized by a typical hydrothermal process. The structure, morphology, optical and electronic properties were researched by comprehensive characterization methods. The photocatalytic performance of flg-C3N4/WO3 NRs nanocomposites was assessed by degrading Rhodamine B (RhB) dye under visible light irradiation. When the loading amount of the flg-C3N4 is 20 wt%, the flg-C3N4/WO3 NRs nanocomposites exhibit the highest activity and the Chemical Oxygen Demand (COD) values decreased by about 64%. The improved light harvesting ability and higher separation efficiency of photoinduced electron–hole pairs by the decoration of flg-C3N4 lead to the boosting photocatalytic performance. In addition, through ESR analysis and a trapping experiment, the photocatalytic mechanism was also researched.