image: A noble-metal-free Co-Ni(OH)2/CdS nanocomposite enables state-of-the-art photocatalytic benzyl alcohol oxidation activity due to the efficient formation of reactive nickel intermediates, which are promoted by photons and heteroatoms. The as-formed Pickering emulsion achieves gram-scale benzaldehyde photosynthesis with high yields, demonstrating the feasibility of sunlight-driven and hydrogen co-production.
Credit: ©Science Bulletin
Researchers Tierui Zhang and Run Shi, along with their colleagues at the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, have developed a noble‑metal‑free photocatalyst that enables highly efficient and selective oxidation of benzyl alcohol to benzaldehyde while co‑producing hydrogen under visible light. The work, published in Science Bulletin, opens a new pathway for sustainable fine chemical synthesis and clean energy generation.
Benzaldehyde is a crucial intermediate in pharmaceuticals, agrochemicals, and fragrances, but its conventional production often involves toxic byproducts or energy‑intensive conditions. Photocatalysis offers a green alternative, yet existing systems face challenges such as low efficiency, poor selectivity, and limited scalability.
A noble‑metal‑free photocatalyst, Co-Ni(OH)2/CdS, achieves a record production rate of 112.0 mmol g−1 h−1 for benzaldehyde, outperforming previously reported photocatalytic systems. The study reveals a photon–heteroatom synergistically promoted nickel‑based redox cycling mechanism: cobalt doping modulates the electronic structure of nickel hydroxide, facilitating the transfer of photogenerated holes and the generation of reactive Ni3+ intermediates, thereby accelerating the dehydrogenation of benzyl alcohol.
By leveraging the amphiphilic catalyst to form a stable Pickering emulsion, the team achieved gram‑scale benzaldehyde synthesis, obtaining 12.4 g of high‑purity product after 350 hours of continuous irradiation, along with 2.7 L of hydrogen. The work demonstrates a promising strategy for the synergistic production of fine chemicals and clean energy, highlighting the scalability of photocatalytic technology for low‑carbon chemical manufacturing.