Lollipop-shaped Co9S8/CdS nanocomposite derived from zeolitic imidazolate framework-67 for the photocatalytic hydrogen production

The unlimited consumption of traditional fossil fuels prompted an urgent need for the new H 2 production strategies to provide green and sustainable energy resources. In this context, Co 9 S 8 has emerged as a potent photocatalyst due to its narrow bandgap. Herein, we describe the synthesis of a recyclable lollipop-shaped Co 9 S 8 /CdS nanocomposite via direct annealing of zeolitic imidazolate framework-67 (ZIF-67) and CdS, as the template and sulfur source, respectively. The close contact of these two materials promotes the electron transfer and enhances the number of active sites toward the desired redox reaction. The special structure of Co 9 S 8 /CdS results in a high photocatalytic H 2 production rate of 1852 μmol h −1 g −1 under visible-light illumination, which is ~200 times higher than that of pure ZIF-67 and Co 9 S 8 . Therefore, this study provides a new method for the preparation of Co 9 S 8 that concomitantly improves the photocatalytic performance of pure ZIF-67 in the H 2 production technology. • CdS and ZIF-67 acted as a sulfur source and a sacrificial template, respectively. • Lollipop-shaped Co 9 S 8 /CdS has been obtained. • A high hydrogen production rate was achieved of 1852 μmol h −1 g −1 . • The plausible mechanism for the photocatalytic reaction was discussed.