Efficient photocatalytic conversion of biomass-derived hydroxyl acids to amino acids over Ni/CdS.

Amino acids, as essential nitrogen-containing compounds, hold significant importance in pharmaceutical and advanced material applications. In this study, we develop a nickel nanoparticle-decorated cadmium sulfide (Ni/CdS) photocatalytic system for the efficient conversion of biomass-derived hydroxyl acids under mild conditions. The optimized catalyst exhibits exceptional performance in the reductive amination of lactic acid to alanine, achieving a reaction rate of 61.0 mmol·gcat-1·h-1 with 92.5 % selectivity, outperforming previously reported noble metal-based catalysts. Furthermore, comprehensive characterizations demonstrate that the unique ultrathin nanosheet morphology of the catalyst facilitates efficient charge carrier transport, while the incorporated nickel species act as an effective electron mediator, synergistically enhancing the photocatalytic activity. This work provides a sustainable and scalable approach for amino acid synthesis, highlighting the potential of non-precious metal photocatalysts for high-value transformation of biomass.