Abstract
[Display omitted]
•Noble metal-free Z-Scheme TiO2/rGO/g-C3N4 nanocomposite is fabricated by pulsed laser ablation in liquid.•This novel hybrid shows significantly enhanced photocatalytic H2 production.•High redox ability and increased photogenerated separation using Z-scheme approach favored photocatalytic performance.•This method can be utilized to fabricate different Z-scheme systems for varies photocatalytic applications.
Constructing nanocomposite structures with favorable charge transfer routes is an effective way to obtain highly efficient photocatalysts. Herein, fabrication of indirect and noble metal-free Z-scheme photocatalytic architecture is demonstrated using pulsed laser ablation in liquids (PLAL) technique for the first time. The as-prepared ternary photocatalyst (denoted as TiO2/rGO/g-C3N4) comprises titanium dioxide (TiO2) nanotubes, reduced graphene oxide (rGO) nanosheets, and graphitic carbon nitride (g-C3N4) nanosheets. The photocatalytic activity of the as-synthesized composite is evaluated by monitoring water splitting. Various analytical techniques were employed to investigate the compositional, morphological, structural, and optical properties of the photocatalysts. The system of TiO2/rGO/g-C3N4 with the weight ratio of TiO2 to g-C3N4 of 2:4 and 1% rGO exhibited the highest hydrogen production rate of 32 ± 1 mmol g−1h−1, which is about 93, 3.8 and 2.6 times higher than those of pure g-C3N4, TiO2, and TiO2/rGO, respectively. This enhanced performance can be ascribed to the strong interfacial bonding (TiO2-rGO-g-C3N4), extended visible light absorption capacity due to higher photo-responsiveness of rGO and g-C3N4, the synergetic effect between TiO2 and g-C3N4 and direct contact between TiO2 and rGO which facilitated efficient separation and transfer of photogenerated charges. This study opens opportunities for the fabrications of different Z-scheme systems for various applications.