Photoinduced enhancement of 137Cs removal by NiFe Prussian blue analogue-alginate hydrogel

•NiFe PB-alginate hydrogel (NiFe-AH) was synthesized by cross-linking with Ni2+.•The Cs+ adsorption of NiFe-AH increased by 1.5 times during light irradiation.•NiFe-AH exhibited higher Cs+ adsorption than commercialized AMP-PAN and KNiFe-PAN.•Weight and volume of NiFe-AH could be drastically reduced after Cs+ adsorption.•The mechanism of photoinduced enhancement of Cs+ adsorption by NiFe-AH was proved.