Photothermal-enhanced bifunctional Bi-doped CdS for coupled H2 evolution and selective alcohol oxidation

Integrating photocatalytic H 2 evolution with selective organic oxidation constitutes a sustainable strategy for coproducing clean fuel and value-added chemicals. However, this technology continues to face significant challenges, including sluggish charge separation, limited product selectivity, and restricted light utilization. Herein, we constructed a Bi-doped CdS (Bi-CdS) photocatalyst through hydrothermal method. The substitutional incorporation of Bi 3+ into the CdS lattice extends the light absorption range to 800 nm, modulates the electronic structure, and induces a localized photothermal effect. Consequently, the optimized 0.5% Bi-CdS catalyst exhibits substantially reduced kinetic barriers for coupled proton reduction and alcohol dehydrogenation, exhibiting a 4.8-fold enhancement in H 2 generation and a 5.1-fold improvement in benzaldehyde production relative to pristine CdS. The selectivity of benzyl alcohol oxidation to benzaldehyde approaches nearly 100%. The photothermal synergy arising from Bi 3+ doping further accelerates the coupled redox reaction, resulting in an enhanced H 2 evolution of 2.46 mmol g -1 h −1 with a simultaneous benzaldehyde production rate of 2.42 mmol g -1 h −1 over the catalyst at 313.15 K. Mechanistic studies identify the Ph(OH)CH· radical as the pivotal intermediate in the selective oxidation pathway. These findings indicate that Bi-doped CdS can function as a promising photothermal-assisted catalyst for simultaneous H 2 production and alcohol upgrading, and we anticipate that this work will offer valuable insights for the rational design of dual-functional photothermal catalysts in solar-driven chemical conversion.