Stable CuCrO2 nanoparticles – ZnO fibres p-n heterostructure system for effective photocatalytic activity

Abstract

Heterostructured photocatalysts were fabricated by coupling electrospun n-type ZnO fibres and hydrothermally derived p-type CuCrO2 nanoparticles. The effect of the amount of CuCrO2 nanoparticles on the photocatalytic activity of the heterostructured photocatalyst was systematically investigated. The formation of the heterojunctions between the two semiconductors was revealed via detailed XRD, XPS, TEM and optical property measurements. The experimental results indicated that the optimal CuCrO2 amount in the composite photocatalyst was 1.0 wt.% due to the optimum doping and surface coverage, higher absorption onset edge, larger absorption intensity and optimum band gap energy. This composite photocatalyst, fabricated by drop casting of CuCrO2 nanoparticle dispersion on ZnO fibres, displayed 30% higher rate constant (k) value compared to the pure ZnO fibres in the degradation of methylene blue dye molecules and reached 93.4% decomposition in 1 h under UV-visible light exposure. The obtained results are highly encouraging in comparison to only UV/light active p-n heterostructured photocatalysts previously reported in literature. Therefore, we believe that the proposed approach here opened the way for simple synthesis of highly-efficient visible light active heterostructured semiconductor photocatalyst systems.