Cu₂O nanoparticles of 5 nm average size have been adsorbed (1.74 wt% loading) on defective graphene (Cu₂O/G) previously obtained by the pyrolysis of alginic acid sodium salt. The Cu₂O crystal phase was determined by XRD. XPS shows that the external layers of the Cu₂O nanoparticles are constituted mainly of Cu⁺ although a certain percentage of Cu^II+ was also present. Cu₂O/G is a photocatalyst for the CO₂ reduction to methane in the presence of sacrificial agents, and the rate of CH₄ production depends on the oxidation potential of the electron donor. This relationship supports a mechanism involving photoinduced charge separation with the generation of electrons and holes. The highest CH₄ formation rate upon UV-Vis irradiation of Cu₂O/G with a 300 W Xe lamp was achieved for dimethylaniline reaching 326 μmol CH₄ per g per h. The spectral response of the Cu₂O photocatalyst shows, however, that the response of the photocatalyst is mainly due to UV irradiation, indicating that light absorption at the low Cu₂O loading on the Cu₂O/G photocatalyst occurs mainly on the graphene component.

中文翻译：

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牺牲电子给体探测石墨烯负载的Cu ₂ O 光催化还原CO ₂的机理†

平均尺寸为5 nm的Cu ₂ O纳米颗粒已吸附（负载量为1.74 wt％）在先前通过藻酸钠盐的热解获得的有缺陷的石墨烯（Cu ₂ O / G）上。通过XRD确定Cu ₂ O晶相。XPS显示，尽管也存在一定百分比的Cu ^{II +}，但是Cu ₂ O纳米颗粒的外层主要由Cu ⁺构成。Cu ₂ O / G是在牺牲剂存在下，CO ₂还原为甲烷和CH ₄速率的光催化剂。产量取决于电子给体的氧化电位。这种关系支持一种机制，该机制涉及光生电荷的分离以及电子和空穴的产生。当二甲基苯胺达到每克每小时326μmolCH _4时，用300 W Xe灯对Cu ₂ O / G进行UV-Vis照射时，最高CH ₄形成速率。但是，Cu ₂ O光催化剂的光谱响应表明，该光催化剂的响应主要是由于紫外线照射引起的，表明在Cu ₂ O / G光催化剂上低Cu ₂ O负载下的光吸收主要发生在石墨烯上。零件。