Nanoconfined Ti3C2@in-situ-grown TiO2 and ruthenium triphenylphosphine (Ru-II) coupled g-C3N4 to construct RuP-Ti3C2@TiO2/EC3N4 dual function nanocomposite for enhancing photocatalytic green hydrogen production

Nanoconfined 2D Ti3C2 MXene@ in-situ grown TiO2 and ruthenium (II) complex (triphenylphosphine, RuP) were synchronously attached with exfoliated g-C3N4 to fabricate a RuP-Ti3C2@TiO2/EC3N4 dual function nanotexture for photocatalytic solar hydrogen production. The Ti3C2@TiO2 was obtained through HF etching, whereas 48 h of etching time was optimal, enabling the highest H2 production through TiO2 photoexcitation. The nanoconfined Ti3C2@TiO2 coupled with EC3N4 boosted 2.34 folds more H2 production due to TiO2/EC3N4 heterojunction formation with Ti3C2 as a cocatalyst to trap and transport charge carriers. Coupling ruthenium complex (RuP) was beneficial to inject excited electrons to enhance EC3N4 photoactivation under visible light, whereas Ti3C2 cocatalyst accepted the photogenerated electrons from EC3N4 through in-situ grown TiO2. The optimized RuP-Ti3C2@TiO2/EC3N4 exhibited a H2 production rate of 1772 µmol g−1 h−1, which was 2.91, 5.16 and 18.02 folds higher than using RuP/EC3N4, Ti3C2/EC3N4 and EC3N4 samples, respectively. The synergistic effect of RuP with Ti3C2@TiO2 promoted H2 evolution without any deactivation of surface stability due to providing excited electrons and preventing their recombination over the exfoliated nanotexture of g-C3N4. Using this new approach to constructing dual-function heterojunctions, it is attractive to excite semiconductors and can increase the lifetime of photoinduced charge carriers. This work provides a facile strategy and new design approach to develop highly efficient and low-cost photocatalysts for future solar energy-assisted sustainable energy conversion systems for different applications.