Lei Xiao,Chaowei Yuan,Peng Chen,Yongyi Liu,Jianping Sheng,Shihan Zhang,Fan Dong,Yanjuan Sun
Due to the intrinsic chemically inert CO2 with the dissociation energy of C═O bond as high as 750 kJ mol–1, low efficiency and selectivity have become the most significant restraints for the practical application of photocatalytic CO2 reduction. Renewing the electronic structure of adsorbed CO2 on the catalyst surface through a rational catalyst design is crucial to achieving performance improvement. Herein, we prepared ZnIn2S4 and Cu-substituted ZnIn2S4 containing both Lewis acid and Lewis base sites as a model system for investigating the activation of CO2 by M–S chemical bonds (M represents a metal site). The Cu–S chemical bond can effectively activate CO2 as a vital electron channel and lower the Gibbs free energy for generating the essential intermediate *COOH. Besides, the Cu0.7-ZnIn2S4 sample displays 74.8% selectivity for reducing CO2 to CO with a rate of 47.2 μmol g–1 h–1, roughly 7.14 times that of ZnIn2S4.
Hui Huang,Meini Li,Mingwei Hao,Liangli (Lucy) Yu,Yongxin Li
A selective and sensitive colorimetric strategy for sulfide analysis was developed using GMP-Cu nanozymes with a laccase-like activity. This research discovered for the first time that sulfide could significantly enhance the catalytic activity of the GMP-Cu nanozymes by about 3.5 folds. The enhanced laccase activities duo to two reasons. First, Cu 2+ in GMP-Cu nanozymes was reduced to Cu + . The other reason was the formation of Cu–S bond which was beneficial to accelerate the electron transfer rate to improve catalytic activity. Therefore, this method showed an excellent selectivity for sulfide. And it had a linear relationship in the sulfide concentration range of 0–220 μmol/L with a detection limit of 0.67 μmol/L. Furthermore, the proposed method was successfully applied to examine sulfide in the food systems. This new method may be used in sulfide detection to improve food quality and safety.