A novel noble-metal-free binary and ternary In2S3 photocatalyst with WC and “W-Mo auxiliary pairs” for highly-efficient visible-light hydrogen evolution

Herein, noble-metal-free In 2 S 3 -WC and In 2 S 3 -based photocatalysts with dual cocatalysts of flower-like MoS 2 and bulk WC were synthesized through a facile solvothermal reaction. Electrochemical results indicated WC increased the interface conductance of photocatalyst and boosted the transference of photogenerated carriers. The optimal In 2 S 3 -WC show a hydrogen production rate of 128.11 μmol·h −1 ·g −1 , which is around 6 times higher than In 2 S 3 -1%Pt (20.73 μmol·h −1 ·g −1 ). The above results demonstrate commercial WC has a crucial impact of replacing precious metal and separating carriers. Morphology characterization exhibited hydrangea In 2 S 3 and flower-like MoS 2 were attached to bulk WC. Gratifyingly, photocurrent, impedance and photoluminescence results demonstrated MoS 2 further effectively separated the photogenerated carriers. Remarkably, the higher hydrogen generation rate of 390.52 μmol·h −1 ·g −1 obtained by the optimal ternary In 2 S 3 -WC-MoS 2 composite was around 3 and 18 times higher than the optimal In 2 S 3 -WC and In 2 S 3 -1% Pt. The photocatalytic results demonstrated that "W-Mo auxiliary pairs" was a great efficient synergistic cocatalyst for In 2 S 3 to increase active sites and improve e - -h + pairs separation for H 2 generation. Furthermore, a probable reaction mechanism of the enhanced photocatalytic H 2 generation was also proposed. This presented research provides an effective concept to design novel and efficient noble-metal-free photocatalyst with "W-Mo auxiliary pairs" for prominent H 2 generation activity.