Rationally Designed Functional Ni₂P Nanoparticles as Co–Catalyst Modified CdS@g‐C₃N₄ Heterojunction for Efficient Photocatalytic Hydrogen Evolution

Abstract

Ni2P nanoparticle contained no precious metal as co‐catalyst to touch up CdS nanorods coupling with graphitic C3N4 for H2 evolution was synthesized successfully by in‐situ fabrication approach. The preparative Ni2P‐CdS/g‐C3N4 composite catalyst exerts remarkable hydrogen production activity and exhibit good photostability in 20 hour cycles. The hydrogen evolution rate is 9.9 times as high as that of pure CdS. Morphological characterization, optical results and electrochemical test proved that special CdS/g‐C3N4 enhanced the transfer of electrons on CdS and g‐C3N4, loading Ni2P co‐catalyst further increased the synergistic effect in photocatalytic properties. Several characterization results such as transmission electron microscopy (TEM), X‐ray diffraction (XRD), The Ultraviolet–visible spectroscopy diffuse reflectance spectroscopy (UV‐vis DRS), Photoluminescence (PL) and nitrogen adsorption‐desorption isotherms (BET) etc. indicate that the Ni2P nanoparticles loaded on the CdS/g‐C3N4 exposed more active sites and facilitated the efficiency of photogenic electron‐hole pairs separation. Optimistically, these results were good consistent with each other. This considerable performance probablely attribute to the special conduction band (CB) and valence band (VB) of CdS and g‐C3N4 which form a heterojuction and the introduction of Ni2P as cocatalyst further extract photogenerated electrons that lower the over potential of H+ redution.

Visible‐Light‐Driven Self‐Coupling of Methylarenes Catalyzed by Ni2P@Cd0.5Zn0.5S Nanoparticles

“…Under the visible light irradiation, photoelectron and hole were separated, then photoelectrons of Cd 0.5 Zn 0.5 S reached the conduction band, and holes stayed at valance band. Then photoelectrons were delivered to cocatalyst Ni 2 P. In the past, Ni 2 P nanoparticles have been employed as cocatalyst to modify CdS@g‐C 3 N 4 heterojunction, and it promoted the separation of photogenerated carriers and enhanced effective electron transfer, which supplied more active sites for the hydrogen evolution reaction . In this work, the free‐radical trapping experiments illustrated that both photo‐electrons and photo‐holes are crucial for the self‐coupling reaction of p ‐xylene, therefore, reducing the recombination of electrons and holes were essential.…”