Structure, morphology and photocatalytic activity of attapulgite/Ag₃PO₄ hybrids synthesized by a facile chemical precipitation route

Attapulgite (ATP)/Ag₃PO₄ hybrids have been synthesized via a facile chemical precipitation route, and we also examined the effect of precursor phosphate types on the structure, morphology and photocatalytic property of the obtained products. It was found that the ATP surfaces were uniformly coated by ultrathin Ag₃PO₄ nanoparticles (NPs) with sizes of 5–20 nm, while the as-synthesized hybrids exhibited the higher photocatalytic activities for methyl orange degradation than the single Ag₃PO₄ crystals although the amount of active species were decreased a lot. The behavior was thus attributed to both the smaller particle sizes and the larger surface. In addition, it was also observed that the photocatalytic activities of those hybrids were dependent on the types of phosphate salts. In details, a few impurities were found in the samples synthesized via Na₃PO₄, while the ones synthesized using two other phosphates (Na₂HPO₄, NaH₂PO₄) exhibited the higher photocatalytic activities and stabilities due to the higher loading amount, smaller size and more uniform coating of Ag₃PO₄ NPs. This work presents a new approach for expanding the possibilities for developing low cost and visible-light responsive photocatalysts.