Synthesis and Photocatalytic Properties of CuO-CuS Core-Shell Nanowires

Abstract

In this study, an efficient method to synthesize CuO-CuS core-shell nanowires by two-step annealing process was reported. CuO nanowires were prepared on copper foil via thermal oxidation in a three-zone horizontal tube furnace. To obtain larger surface area for photocatalytic applications, we varied four processing parameters, finding that growth at 550 °C for 3 h with 16 °C/min of the ramping rate under air condition led to CuO nanowires of appropriate aspect ratio and number density. The second step, sulfurization process, was conducted to synthesize CuO-CuS core-shell nanowires by annealing with sulfur powder at 250 °C for 30 min under lower pressure. High-resolution transmission electron microscopy studies show that a 10 nm thick CuS shell formed and the growth mechanism of the nanowire heterostructure has been proposed. With BET, the surface area was measured to be 135.24 m2·g−1. The photocatalytic properties were evaluated by the degradation of methylene blue (MB) under visible light irradiation. As we compared CuO-CuS core-shell nanowires with CuO nanowires, the 4-hour degradation rate was enhanced from 67% to 89%. This could be attributed to more effective separation of photoinduced electron and hole pairs in the CuO-CuS heterostructure. The results demonstrated CuO-CuS core-shell nanowires as a promising photocatalyst for dye degradation in polluted water.

From MOF-199 Microrods to CuO Nanoparticles for Room-Temperature Desulfurization: Regeneration and Repurposing Spent Adsorbents as Sustainable Approaches

“…64 This behavior has been observed in CuO and CuO−CuS photocatalysts as well, where the CuO−CuS photocatalyst showed better MB degradation efficacy. 62 Here, sulfur was present as sulfide and sulfate in the exhausted adsorbents, which improved their photocatalytic activity.…”

Copper Oxide-Based Photocatalysts and Photocathodes: Fundamentals and Recent Advances

“…Copper-zinc oxide nanoflowers prepared by hydrothermal route showed the hydrogen evolution in pure water, while in the presence of sacrificial hole scavenger (triethanolamine) the yield of reaction increased four times [ 180 ]. Further examples of photo(electro)catalyst type-II heterojunctions are: WO 3 /Cu 2 O [ 181 ], In 2 O 3 /CuO [ 182 , 183 ], NiO/Cu 2 O [ 184 ], CeO 2 /CuO [ 185 ], CdS/Cu 2 O [ 186 ], ZnS/Cu 2 O [ 187 ] and CuS/CuO [ 188 ].…”

A Comparative Evaluation of Physicochemical Properties and Photocatalytic Efficiencies of Cerium Oxide and Copper Oxide Nanofluids

“…However, there can be additional reasons based on the properties of the respective NPs in the NF formulation. Based on the literature, one can notice that CuO NF and CeO 2 NF exhibited higher rate constants for photodegradation of MB than many of the reported rate constants of the conventional nanoparticles-based photocatalysts, such as ZnO (0.022 min −1 ) [83], TiO 2 (0.025 min −1 ) [84] and CdS (0.0079 min −1 ) [85] and also rate constants of the CuO-based nanocatalysts, such as CuO nanowires (0.0046 min −1 ) [86] and CuO-CuS core-shell nanowires (0.0097 min −1 ) [86]. Our results gave a clue that the metal oxide nanoparticles-when dispersed in the form of NFs-exhibit enhanced photocatalytic performances.…”