Facile regulation of cuprous oxide microcrystal morphology and planes for visible light photocatalytic degradation

Abstract

Cuprous oxide (Cu2O) microcrystal is an excellent material for absorbing visible light and photo‐catalyzing various water pollutants. The photocatalytic performance of Cu2O crystal mainly depends on its morphology and exposure surface. In this study, Cu2O crystals have been successfully fabricated at room temperature. Morphology and the proportion of exposed crystal faces are regulated by a simple method with hydrazine hydrate as the reducing agent. The experimental results unveiled that high dosage of hydrazine hydrate tends to produce crystals with spherical and low (111) plane ratios, while low dosage of hydrazine hydrate provides an excellent condition for the formation of octahedral microcrystal with high proportion of (111) planes. The photocatalytic degradation efficiency of methylene blue (MB) in visible light increased with the proportion of (111) planes. Analysis shows that the better crystallinity and conductivity of the octahedron structure improved the utilization rate of photogenerated carriers, while the unsaturated Cu on the (111) planes as the active site promotes the decomposition of the pollutants.

Dandelion-Like Nanostructured Cu/Cu2O Heterojunctions with Fast Diffusion Channels Enabling Rapid Photocatalytic Pollutant Removal

“…However, Cu 2 O-based catalytic applications are limited by the rapid recombination of photogenerated electron–hole pairs, resulting in poor photocatalytic performance . To overcome this bottleneck, numerous strategies have been proposed to improve the photocatalytic activity of Cu 2 O, including developing nanostructured hollow catalysts with exposed active facets. , For example, Shang et al. found that Cu 2 O nanocrystal with the {110} or {111} exposed facets could deliver excellent photocatalytic reactivity due to the surface dangling Cu atoms which led to strong interactions between Cu 2 O and negatively charged molecules .…”

“…4 To overcome this bottleneck, numerous strategies have been proposed to improve the photocatalytic activity of Cu 2 O, including developing nanostructured hollow catalysts 5 with exposed active facets. 6,7 For example, Shang et al found that Cu 2 O nanocrystal with the {110} or {111} exposed facets could deliver excellent photocatalytic reactivity due to the surface dangling Cu atoms which led to strong interactions between Cu 2 O and negatively charged molecules. 8 The nanostructured material provides larger surface area and significantly enhanced mechanical stability, making it suitable for photocatalytic activities.…”