Interfacial engineering of Ti3C2Tx/TiO2 2D nano-heterostructures for high performance photocatalytic and electrocatalytic hydrogen evolution

Herein, we have in situ synthesized Ti 3 C 2 T x /TiO 2 nano-heterostructures by varying MIL-125 concentration from 0.5 to 10 wt% relative to Ti 3 C 2 T x . Electron microscopy showed TiO 2 nanospheres on the surface and intercalated between 2D Ti 3 C 2 T x layers. UV-Vis spectra revealed absorption edges at 720 nm and 360 nm respectively for Ti 3 C 2 T x and TiO 2 . The TM-3 sample exhibited the highest photocatalytic H 2 generation at 564.6 μmol/0.1 g with an apparent quantum yield of 1.1%, outperforming pristine Ti 3 C 2 T x by 8.5 times. Electrochemical data supported this enhancement, showing a Tafel slope of 78 mV·dec −1 , a low overpotential of 75 mV at −10 mA cm −2 in 1 M KOH, and excellent stability for 30 hours. TM-3 achieved a double-layer capacitance of 5.92 mF cm⁻², 1.4 and 1.6 times higher than MIL-125 and Ti 3 C 2 T x respectively. In-situ TiO 2 intercalation improves interfacial charge transfer and further steady-state PL, time-resolved PL decay, and impedance spectroscopy confirmed the efficient electron transport mechanism.