ZnO Nanoparticle-Decorated CeO2 Nanospheres for Cataluminescence Sensing of H2S

Abstract

Cataluminescence is a kind of interesting chemiluminescence phenomenon on the gas–solid catalytic interface, and highly efficient cataluminescence is extremely anticipated. A CeO2/ZnO nanocomposite catalyst is successfully fabricated via the facile pyrolysis of a CeO2/ZIF-8 sacrificial precursor. Compared with CeO2 nanoparticles without modification, the CeO2/ZnO nanocomposite demonstrates a remarkable cataluminescence performance toward H2S, giving a 130 times increase in cataluminescence intensity, while ZnO nanoparticles derived from pure ZIF-8 do not show any luminescence signal. Moreover, the relationship between the CeO2/ZnO nanocomposite structure and the catalytic performance of H2S is further excavated via Raman spectroscopy and XPS technique. The results indicate that the improved cataluminescence toward H2S could be attributed to the capture-oxidation-release synergistic effect. H2S molecules are effectively captured by ZnO, subsequently catalytically oxidized on CeO2 with abundant oxygen vacancy, and finally released into the gas phase. Consequently, higher efficiency of catalytic luminescence is obtained owing to the synergic effect between CeO2 and ZnO components, and the detection limit of this proposed H2S sensor is as low as 9.50 ng·mL–1. The proposed capture-oxidation-release synergetic mechanism for an enhanced catalytic oxidation property is of great significance in the rational design and engineering of advanced catalysts for diverse application demands.