Visible-light driven photocatalyst of CdTe/CdS homologous heterojunction on N-rGO photocatalyst for efficient degradation of 2,4-dichlorophenol

CdTe nanoparticles modifying leafy CdS homologous semiconductor heterojunctions on nitrogen-doped reduced graphene oxide with solar full spectrum response is synthesized by a simple hydrothermal method and solvothermal method, and investigate their photocatalystic degradation of 2,4-dichlorophenol (2,4-DCP). The obtained CdTe/CdS/N-rGO composites show stronger intensity of photocurrent and longer lifetime of photon-generated carrier than CdTe/CdS and raw CdS, especially by which 70% 50 mg/L 2,4-DCP could be decomposed under visible light irradiation within 6 h. These result from those CdTe nanoparticles have good optical absorption coefficient to effectively absorb more photons and form electronic traps on its surface atoms, and construct homologous semiconductor heterojunctions between CdTe and leafy CdS to change movement pathway of photogenerated charge carriers, further prolonging the lifetime of electrons and holes, and loading nitrogen-doped reduced graphene oxide (N-rGO) could not contribute to electrons transfer, but also provide more active sites to improve the whole photocatalytic ability. These are further confirmed by those that high-resolution transmission electron microscopy (HRTEM) shows that crystal lattices of CdTe and CdS are staggered and the diffuse reflectance spectra (DRS) demonstrated absorption edge of CdTe/CdS/N-rGO get tremendous improved, even ternary composites could response in solar full spectrum. The new approach may provide some inspirations for constructing homologous heterojunctions structure on materials as support with efficient photocatalytic performance.