The effect of transition metal oxides in the La/TiO₂ structure for the photocatalytic degradation of malachite green under UV and visible light irradiation

Herein, La@M_xO_y/TiO₂ (M = V, Cr, Mn and Fe) composite catalysts were prepared based on the sol–gel method as an effective adsorbent and photocatalyst for the degradation of malachite green from an aqueous solution under UV–Vis light. Under experimental conditions, a maximum adsorption capacity of 57.10% for the malachite green dye was achieved with La@Fe₂O₃/TiO₂. Moreover, this composite showed 78.62% photodegradation efficiency for malachite green. A quadratic model constructed using the response surface method showed that the maximum efficiency of photodegradation of malachite green can be achieved at pH 11 and a process time of 35 min.