Photocatalysis provides a promising opportunity for selective oxidation of biomass to high-value chemicals under mild conditions. The key to realize this transformation is to design a cost-effective and environmentally friendly photocatalyst. Here, we report the preparation of a carbon nitride photocatalyst with controllable carbon/nitride (C/N) ratio and its application in the selective photocatalytic synthesis of lactic acid from biomass-derived monosaccharides. Reasonable C/N ratio in the catalyst can significantly enhance the visible light absorption range and accelerate the mobility of photogenerated carriers. The obtained photocatalyst exhibited excellent photocatalytic activity, yielding 76.8% lactic acid. All of the h⁺,·O₂^-,·OH and ¹O₂ are beneficial for lactic acid production, and the·O₂^- plays a major role. Furthermore, the photocatalyst exhibited excellent reusability and universality. The 1000-fold scale-up experiments indicated that the system has potential for industrial production of lactic acid. Therefore, the present work offers a promising example for photocatalytic reforming of biomass.

光催化为在温和条件下将生物质选择性氧化为高价值化学品提供了有希望的机会。实现这种转变的关键是设计一种具有成本效益且环保的光催化剂。在这里，我们报道了一种碳/氮化物 (C/N) 比可控的氮化碳光催化剂的制备及其在从生物质衍生的单糖中选择性光催化合成乳酸中的应用。催化剂中合理的C/N比可以显着提高可见光吸收范围，加速光生载流子的迁移。所得光催化剂表现出优异的光催化活性，乳酸产率为76.8%。所有的 h ⁺ ,·O ₂ ^- ,·OH 和¹ O₂有利于乳酸的产生，其中·O ₂ ^-起主要作用。此外，该光催化剂表现出优异的可重复使用性和通用性。1000 倍放大实验表明该系统具有工业生产乳酸的潜力。因此，目前的工作为生物质的光催化重整提供了一个有前景的例子。