Ti@TiO2/Ni nanocomposite for efficient photothermal hydrogen production

This study reports the synthesis of a Ti@TiO 2 /Ni nanocomposite containing 20 wt% Ni via sonohydrothermal treatment combined with ultrasonic reduction of Ni 2+ using hydrazine. The composite exhibited notable photothermal activity toward hydrogen production in glycerol solution, achieving a rate of 4.41 mmol h −1 g −1 at 94 °C, which is 5.5 times higher than bare TiO 2 with an activation energy of 22 ± 1.5 kJ mol −1 . Interestingly, methane (CH 4 ) formation was observed exclusively in the Ni-containing composite, attributed to a Ni-catalyzed methanation pathway. Photoelectrochemical measurements revealed that Ni incorporation does not enhance the photocurrent response, suggesting that the improved performance arises primarily from surface catalytic effects and thermally-assisted reaction pathways rather than enhanced charge separation. These findings demonstrate that Ni modifies the reaction pathway of Ti@TiO 2 , enabling dual H 2 and CH 4 production.