Self-regenerative and self-enhanced smart graphene/Ag3PO4 hydrogel adsorbent under visible light

A new self-regenerative and self-enhanced smart adsorbent was synthesized by hybridizing the photocatalyst Ag3PO4 nanospheres into a 3D reduced graphene oxide (rGO) hydrogel, which was then used to absorb and mineralize the artificially synthesized dyes methylene blue (MB) and methyl orange (MO). The results indicated that Ag3PO4 particles anchored on the rGO sheets densely and firmly with a similar to 20 nm average diameter. The large specific surface area (SSA) (similar to 100.29 m(2) g(-1)) of the samples could provide many adsorption sites for organic dyes to get good removal effectiveness. The results showed that the 3D graphene/Ag3PO4 composites exhibited excellent removal effectiveness of MB and MO as well as reusability. Especially, the adsorption ability of the adsorbent increased greatly after recycling one-time. The negatively charged functional groups of rGO sheets could attract silver ions (Ag+), which could help the Ag3PO4 particles anchor onto the rGO sheets. The rGO hydrogel has adsorption ability toward dyes, which can help increase the contact chance between dyes and nanoparticles Ag3PO4. The positive effects between Ag3PO4 and rGO could be attributed to the adsorption activity and photocatalytic properties. This study provides a green way to fabricate self-regenerative and self-enhanced smart hydrogel adsorbents under visible light.