Regulating the crystal phase and morphology of XMoO4 through adjusting the ratio of iron and cobalt for significantly boosted photocatalytic degradation of methylene blue and tetracycline

Abstract

Regulating the mineral phase and morphology, as one kind of new strategy for the enhancement of photocatalytic properties, displayed notable advantages in promoting the charge transfer efficiency and achieving low recombination probability of photo-generated electron and hole. Herein, novel composite photocatalysts of XMoO₄ (X = Fe and Co) were systematically regulated and synthesized successfully via adjusting the proportion of iron and cobalt. The photocatalytic degradation of methylene blue (MB) and tetracycline (TE) was conducted under visible light. It was proved that the composite photocatalyst (C7F3), with the optimal cobalt/iron ratio 7:3, displayed nanosheet morphology and notable visible light absorption, and the band gap was 1.60 eV. Besides, compared to other materials, C7F3 demonstrated the most robust photodegradation ability to remove MB and TE, which was attributed to the excellent photoelectric efficiency of C7F3. Also, the composite exhibited favorable photocatalytic stability. Furthermore, photoelectric testing and density functional theory (DFT) calculations illustrated that C7F3 photocatalyst exhibited the strongest photocurrent response, the lowest charge transfer resistance and probability of photo-generated electron–hole recombination, and the most suitable bandgap width and band position (− 0.1902 to 1.4098 V). Additionally, the superoxide radicals, photo-generated electrons and holes synergistically contributed to pollutants degradation in photocatalytic system.