Exploiting efficient and low-cost cocatalyst with a facile grafting strategy is of critical importance for significantly boosting the photocatalytic H₂-evolution activity. In this study, S²⁻-adsorbed MoS_x nanoparticle as a superior H₂-evolutoin cocatalyst was successfully grafted on the TiO₂ surface to greatly boost its photocatalytic activity via one-step lactic acid-induced synthesis strategy. Herein, the lactic acid can induce the homogeneous production of amorphous MoS_x (a-MoS_x) nanoparticles from MoS₄²⁻ precursor, while the symbiotic S^2- ions can be easily and availably self-adsorbed on the a-MoS_x surface, resulting in the formation of S^2--adsorbed a-MoS_x nanoparticles with a small size of 0.5−3 nm. Photocatalytic results manifested that the S²⁻-adsorbed MoS_x nanoparticles could dramatically facilitate the H₂-generation rate of TiO₂ photocatalysts (3452 μmol h^-1 g^-1, AQE = 16.5 %). In situ irradiated XPS in conjunction with transient-state PL and photoelectrochemical tests reveal that the improved H₂-generation activity can be ascribed to the synergistic effect of boosted interfacial charge transfer from TiO₂ to S²⁻-adsorbed MoS_x and the superior H₂-evolution reaction on self-adsorbed S²⁻ ions. In addition, the S²⁻-adsorbed MoS_x nanoparticles can also act as the general H₂-generation cocatalyst to obviously promote the activity of other typical host photocatalysts such as g-C₃N₄ and CdS. This work provides an innovative approach to develop high-efficiency MoS_x-based cocatalyst with boosted interfacial charge transfer toward highly efficient photocatalytic materials.

利用有效的接枝策略开发高效，低成本的助催化剂对于显着提高光催化H _2的进化活性至关重要。在这项研究中，将S ^2-吸附的MoS _x纳米粒子作为一种优良的H _2-外泌尿素助催化剂成功地接枝到TiO ₂表面上，通过一步法乳酸诱导的合成策略极大地提高了其光催化活性。本文中，乳酸可以诱导从MoS ₄ ^2-前体均匀生成非晶态MoS _x（a-MoS _x）纳米颗粒，而共生S ^2-离子可以轻松，有效地自我吸附在a-MoS _x表面，导致形成S ^2-吸附的a-MoS _x纳米颗粒，尺寸为0.5-3 nm。光催化结果表明，S ²⁻吸附的MoS _x纳米颗粒可以显着促进TiO ₂光催化剂的H ₂生成速率（3452μmolh ^-1  g ^-1，AQE = 16.5％）。原位辐照XPS结合瞬态PL和光电化学测试表明，改善的H ₂生成活性可归因于TiO促进界面电荷转移的协同效应。₂到S ^2-吸附的MoS _x和对自吸附S ^2-离子的优良H ₂演化反应。此外，吸附有S ^2−的MoS _x纳米颗粒还可以充当一般的H ₂生成助催化剂，从而明显提高其他典型主体光催化剂（如gC ₃ N ₄和CdS）的活性。这项工作提供了一种创新的方法来开发基于MoS _x的高效助催化剂，同时将界面电荷转移到高效的光催化材料上。