TiO₂/PANI/Graphene–PVA Hydrogel for Recyclable and Highly Efficient Photo-Electrocatalysts

In this paper, TiO 2 /PANI/graphene–PVA hydrogel (TPGH) is fabricated by combining TiO 2 /PANI/graphene powder with poly(vinyl alcohol) (PVA) hydrogel. X-ray diffraction (XRD) patterns, Fourier transform infrared (FTIR) spectra, and photocurrent patterns indicated that TiO 2 /PANI/graphene had an excellent photoelectrical response because the introduction of polyaniline (PANI) into the TiO 2 system can promote the separation of photogenerated electrons and holes. Meanwhile, graphene can be used as an acceptor for photogenerated electrons in composites and can prevent carrier recombination and increase charge transfer. This hydrogel exhibits recyclability and excellent photo-electrocatalysis properties, which is attributed to the excellent photoelectric response properties of TiO 2 /PANI/graphene. The hydrogels with the best photocatalytic performance can degrade methyl orange and RhB more than 98% within 60 min and bisphenol A more than 97% within 150 min. Moreover, 88% degradation rate remained after five cycles for hydrogels, which indicated that the hydrogels had good cycling performance. The findings provide a new strategy for the construction of TiO 2 /PANI/graphene photocatalysts and pave an alternative way to the design and synthesis of recyclable hydrogel photocatalysts.