Ingenious Design of CoAl-LDH p-n Heterojunction Based on Cul as Holes Receptor for Photocatalytic Hydrogen Evolution

Reasonable design of heterojunction can greatly improve the photocatalytic hydrogen evolution activity of materials. Herein, p-n heterojunction of 2D/3D structure is constructed by the nanosheet of CoAl-LDH and rock-like Cul. The introduction of Cul can make CoAl-LDH disperse better, which brings more reaction sites for the hydrogen evolution reaction. Meanwhile, the 2D/3D structure is conducive to the construction of p-n heterojunction between the CoAl-LDH and Cul. The optical and electrochemical properties of the material indicate that the separation and transference of photon-generated carriers are promoted by the p-n heterojunction. The activity of composite catalyst (CI-10) reaches a maximum of 3.59 mmol g(-1) h(-1) which is 28.5 times higher than that of Cul. Furthermore, the influence of the amount of Cul and pH value on the hydrogen evolution reaction is explored. Based on the band structures of CoAl-LDH and Cul, the mechanism of photocatalytic reaction of CI-10 is proposed. The p-n heterojunction constructed with the Cul as hole receptor provides a new way to enhance the activity of photocatalytic H-2 evolution.

Automated summary

Reasonable design of heterojunction is crucial for enhancing the photocatalytic hydrogen evolution activity. In this study, a p-n heterojunction of 2D/3D structure was constructed using CoAl-LDH nanosheets and rock-like CuI. The introduction of CuI improved the dispersion of CoAl-LDH and provided more reaction sites for hydrogen evolution. The optical and electrochemical properties demonstrated that the p-n heterojunction promoted the separation and transfer of photon-generated carriers. The composite catalyst, CI-10, exhibited a significantly higher activity of 3.59 mmol g(-1) h(-1), which was 28.5 times higher than that of CuI. Furthermore, the influence of CuI dosage and pH value on the hydrogen evolution reaction was investigated, and a mechanism for the photocatalytic reaction of CI-10 was proposed.