Synergistic effects of cocatalyst and homojunction/heterojunction with boosted photocatalytic H2 evolution over Zn0.5Cd0.5S/NDs

For improved photocatalytic hydrogen evolution, building heterojunction structures has been considered as a promising strategy to promote charge separation and transportation. Herein, an in-situ hydrothermal process was used to prepare the novel twin Zn0.5Cd0.5S/NDs (ZCND-x) homojunction/heterojunction photocatalyst of nanodiamonds (NDs) dots anchored twin Zn0.5Cd0.5S (T-ZCS). Among all the composites, the ZCND-10 hybrid exhibits a much higher H2 performance of 160.035 mmol/g/h with a mixture of Na2S and Na2SO3 (pH = 13.82) as hole eliminator agent, which is considerably 5.3 times that of pure T-ZCS nanoparticles. Furthermore, the optimum apparent quantum yield (AQY) of ZCND-10 is up to 32.42% at λ = 420 ± 15 nm. At the same time, ZNCD-10 heterojunction owns excellent H2 evolution cycle activity and photostability. Simultaneously, photocatalyst depicts good photocatalytic overall water splitting performance. Meanwhile, experimental characterization results indicate extend light response, high surface area, as well as accelerate charge separation of homojunction/heterojunction induced phase junctions by the interfacial synergistic effect between T-ZCS and NDs, endowed with excellent H2 evolution performance and chemical stability. Theoretical work functions, electron density distribution and in-situ XPS further clarify the electron transfer pathway between T-ZCS and NDs. The potential mechanism of photocatalytic enhancement of ZCND-x hybrid is proposed, which may lead to a new thinking for the efficient preparation of other photocatalytic materials.