Promotion effects of microwave and carbon dots interactions on hydrolysis for highly efficient hydrogen production

In this study, carbon dot-doped Co₃O₄ was synthesized and used in NaBH₄ hydrolysis under both microwave and conventional heating. Microwave energy significantly increased the hydrogen generation rate with a CD-doped Co₃O₄ catalyst, ranging from 34.1 % at 35 °C to 70.7 % at 55 °C compared with conventional heating. This improvement is due to the combined contribution of microwave thermal and non-thermal effects. These phenomena greatly enhances the effective collision frequency of the reaction species at the interface of the catalyst. Furthermore, the kinetics of NaBH₄ hydrolysis with the CD-doped Co₃O₄ catalyst follows a zero-order kinetic model. Under microwave irradiation, the HGR of the CD-doped Co₃O₄ catalyst was 4.5 times that of pure Co₃O₄ at 40 °C. Incorporating carbon dots (CDs) into the Co₃O₄ matrix simultaneously enhances microwave absorption, increases hydrophilicity, and reduces the activation energy needed for breaking down O–H bonds in H₂O. These improvements are expected to boost the overall catalytic performance.