Fabrication Of Metal/Carbon Nitride Composites And Its Photoelectrocatalytic Behaviors On Small Organic Molecules And Biomolecules

Photoelectrocatalysis over metal/semiconductor nano-composites has attracted significant attention due to their unique performance, especially in hydrogen production and solar energy conversion. Different metallic nanoparticles and their oxides can be either added into the crystallattice by doping and implanting, or anchored onto the semiconductor surface by coating and depositing. Both approaches can effectively promote the electron-hole pairs separation and improve the photoelectrocatalytic performance.Graphitic carbon nitride (g-C3N4), a novel semiconductor photocatalyst, has recently attracted researchers’great interest because of its high stability, nontoxicity, and ease of preparation in large scale. However, less attention has been paid to the application of C3N4-based materials in photoelectrocatalysis due to their large resistance. Gold nanoparticles (Au NPs) incorporated with types of semiconductors (such as TiO2, ZnO, Al2O3, CeO2) could effectively reduce the resistance of semiconductors and demonstrated unexpectedly high catalytic activity towards various oxidative transformations. Therefore, in this study, Au/g-C3N4nanocomposites were prepared by loading gold nanoparticles on the surface of g-C3N4via a facile citrate-reduction method, and then were used to catalyze the oxidation of small organic molecules. The photoelectrocatalytic results demonstrated that Au/g-C3N4significantly enhanced the oxidation of formic acid, formaldehyde and ethanol by lowering oxidation potential and being free from CO poisoning.Nickel (a kind of transition metals) and Ni-base material have been widely applicated in electrooxidation of small biomolecules (such as amino acids, glucose) for their unique properties such as low cost, good electrochemical and catalytic activity. In this work, Ni was deposited on the surface of Au/g-C3N4by multi-potential steps, and then were used to catalyze the oxidation of glucose. The results indicated that Ni/Au/g-C3N4showed a better catalytic activity towards the oxidation of glucose and good ability to discriminate the interfering species such as uric acid and ascorbic acid.