Nanotwinned Structure-Dependent Photocatalytic Performances of the Multipod Frameworks of Cu7S4 Hollow Microcages

Abstract

The 14-pods Cu 7 S 4 hollow microcages wholly exposed with nanotwinned building blocks were successfully prepared by an ethanol-assisted sacrificial Cu 2 O template approach. Its photocatalytic activity for the degradation of methylene blue (MB) was determined. The results suggest that the Cu 7 S 4 microcages with nanotwinned building blocks possess higher catalytic activity than the Cu 7 S 4 microcages without the nanotwinned structures, suggesting that the special nanotwinned components can improve the catalytic performance of the multipod framework. Further investigate reveals that the nanotwins inside the Cu 7 S 4 microcages can facilite the transport of free charges, decrease the recombination of photoinduced electrons and holes, and elongate the lifetime of the electron-hole pairs. Our work will provide powerful evidence that the nanotwinned building blocks of the synthesized Cu 7 S 4 microcages play a crucial role for the high catalytic activity.

Mechanochemical synthesis of non-stoichiometric copper sulfide Cu1.8S applicable as a photocatalyst and antibacterial agent and synthesis scalability verification

“…The results of the photocatalytic experiments show that the photocatalytic activity of our products is competitive to that detected for similar compounds reported in ref. 27–35, completely decomposing the organic dye MO in just 2 hours of irradiation. Moreover, the fact that the obtained products exhibit photocatalytic activities under visible light irradiation is a clear advantage over the reports available in the literature 27–31 which describe activity only under UV light irradiation.…”

“…27–35, completely decomposing the organic dye MO in just 2 hours of irradiation. Moreover, the fact that the obtained products exhibit photocatalytic activities under visible light irradiation is a clear advantage over the reports available in the literature 27–31 which describe activity only under UV light irradiation. A control experiment of irradiating a solution of MO in the presence of hydrogen peroxide was also carried out (black curves), however, almost no activity was achieved, which proves that the decomposition of MO was due to the photocatalytic activity of our catalysts.…”

“…Without the presence of hydrogen peroxide, both the Cu 1.8 S_LAB and Cu 1.8 S_IND samples show lower photocatalytic activity (the results are not shown here), but this has also been observed in many previous studies on the photocatalytic activity of non-stoichiometric copper sulfides. 29–31 When using hydrogen peroxide, the catalyst first reacts with it to produce radicals, which react with the organic compounds afterwards. 31 Possible pathways for the formation of radicals are presented in the following 4 equations:Cu x S y + hν → h vb + + e cb − H 2 O 2 + h vb + → ˙OOH + H + H 2 O 2 + e cb − → ˙OH + OH˙OOH → ˙O 2 + H + …”

“…23–26 A similar situation is in the photocatalytic applications of copper sulfides, 27,28 however, in this case, the reports on non-stoichiometric Cu x S y photocatalysis are more numerous than in the case of antibacterial action. 29–36…”

Construction of Cu2O@Cu1.75S Core‐shell Octahedrons for Enhanced NO2Gas Sensing at Low Temperature

“…The gas sensing materials based on Cu 2 O have also some disadvantages, such as highpower consumption, safety problems and weak sensitivity to low concentration NO 2 detection, which hampers their practical application in gas sensors. According to the recent reports, the band gap of non-stoichiometric p-type Cu x S is 1.2-2.0 eV [14,15]. Therefore, Cu x S is a prospective material for gas sensing at low temperature.…”