Facile and single-step route towards ZnO@C core–shell nanoparticles as an oxygen vacancy induced visible light active photocatalyst using the thermal decomposition of Zn(an)2(NO3)2

Abstract

Zinc oxide–carbon (ZnO@C) core–shell nanoparticles were synthesized using a facile and single-step method, which involved the thermal degradation of a zinc aniline nitrate complex in methanol. The formation of ZnO and carbon was observed during the early stages of synthesis (>200 °C), whereas a further increase in the temperature determines the level of the carbon coating. Transmission electron microscopy confirmed that the ZnO@C nanoparticles obtained at 600 °C were ∼100 nm in size with a uniform 5–20 nm thick carbon coating. The nano-coating of carbon on ZnO along with the presence of oxygen vacancies promoted its photocatalytic activity under visible light with higher efficiency for the photodegradation of rhodamine B than bare ZnO. The two probable pathways for the visible activity and the enhanced photodegradation capacity of ZnO@C core–shell nanoparticles are also discussed. The synthesized ZnO@C core–shell nanoparticles exhibited very good stability and recyclability, highlighting their potential use as an efficient visible light driven photocatalyst for pollutant degradation.