Ni2+ grafted Ag3PO4: Enhanced photocatalytic performance under visible light

Abstract

New visible light photocatalysts based on Ag3PO4 (AgP) grafting with Ni2+ at three different percentages have been synthesized by coprecipitation-hydrothermal method. SEM/EDX, XRD and FTIR characterization revealed that all the samples present particles with a smooth surface spherical morphology. Dissimilarities were recorded in the particle size, grafted Ag3PO4 (Ni-AgP) undergo a reduction in diameter with the increase of the content of Ni2+. The unit cell parameters of the centered cubic structure of the samples are different from each other which suggested a possible integration of nickel in the outer layers but with the denial of the possibility of reaching the inner layers. The photocatalytic performance was evaluated in methyl orange (MO) degradation under different conditions of solution pH and MO concentration. It was found that nickel grafting resulted in enhanced photocatalytic activity which is correlated to Ni2+content. The enhancement in the performance is attributed to the synergistic effect of AgP and surface-suspended Ni2+ clusters which serve as acceptors of photogenerated electrons leading to their separation from holes. This action aids in the intense production of active superoxide radicals and preserves the recombination of holes. These two potent species have been confirmed to be responsible for the photocatalytic process according to scavengers’ effect. Concerning the reusability, 6%Ni-AgP presents a good stability alongside its excellent photocatalytic activity.