Tailoring hierarchical porous TiO2 based ternary rGO/NiO/TiO2 photocatalyst for efficient hydrogen production and degradation of Rhodamine B

Abstract

Abstract This study reports a facile and cost effective approach for synthesizing a ternary photocatalyst rGO/NiO/TiO2 (RGNPT) based on three-dimensionally hierarchical porous TiO2 (PT) particles, rGO and NiO as a cocatalyst for efficient photocatalytic hydrogen generation. The efficient junction architecture of RGNPT was observed from the TEM study. The composite s morphology was tuned by varying the weight ratio variation of graphene oxide (5, 7.5, and 10 Wt%). The obtained material showed impressive photocatalytic efficiency for H2 production in aqueous methanol suspension. The p-n junction hybrid composite RGNPT-7.5Wt% showed superior activity towards H2 production yield 8,215 µmolg−1 after 4 h of light irradiation and apparent quantum yield efficiency 9.19%. The photocatalyst shows promising results of 88% of photo-degradation efficiency to Rhodamine B (Rh-B) dye. The RGNPT-7.5Wt% demonstrated the higher current density 0.16 µAcm−2 whereas NiO-porous TiO2 (NPT) showed ten folds lower of 0.017 µAcm−2 using Ag/AgCl electrode. The electron impedance spectroscopic results of RGNPT-7.5Wt% heterostructure exhibited higher photocurrent response and lower charge transfer resistance and significantly accelerate the electrons transfers across the NPT and NiO. Photoluminescence lifetime of RGNPT-7.5Wt% (τ\xa0=\xa03.21\xa0ns) is 16 times higher than porous TiO2 (τ\xa0=\xa00.10\xa0ns). This work manifestates that hierarchical porous TiO2 and rGO graphene plays a vital role in the electron transfer pathway, which is further considered an excellent strategy for synthesizing the ternary composites and enhancing photocatalytic hydrogen production.