Shape-dependent synthesis and photocatalytic degradation by Cu2O nanocrystals: Kinetics and photocatalytic mechanism

In this study, Cu2O crystals with different morphologies were synthesized to investigate the effect of exposed crystalline facets on photocatalytic degradation efficiency. By adjusting the addition amount of PVP, different morphologies of Cu2O crystals were obtained, such as cubic, decahedral, octahedral, etc. XRD, SEM, and TEM characterizations were used to observe the properties of the synthesized Cu2O in terms of morphology, size, and lattice structure. The results showed that the octahedral cuprous oxide had the strongest photocatalytic degradation effect (78.3%). The study also explored the connection between different crystalline facets and MO microstructure, and the effect of crystalline facet selectivity on the pre-absorption and photocatalytic degradation of MO. Density Functional Theory (DFT) calculations were used to investigate the connection between the energy level structure of different crystalline facets of Cu2O and its photocatalytic activity. Finally, based on the experimental analysis and theoretical calculation, a new charge separation model on crystalline surface was proposed.