A nanosandwich made from Ag nanoparticles (Ag NPs) arrays, the two-dimension single-layer graphene (SG) and metallic Cu contact was constructed for the hydrogen peroxide (H₂O₂) generation utilizing solar energy without an external bias. The shifting of binding energy towards lower energy in Ag core-level electronic spectrum is an evidence of strong coupling between Ag and graphene, which can efficiently transfer hot-holes from Ag to Cu by a built-in electric field so that the hot-electrons on Ag NPs are directly utilized to initiate the H₂O₂ generation. This Ag-graphene-Cu nanosandwitch can provide a stable photocurrent of −15.8 μA cm⁻², a stable photovoltaic voltage of 17.5 mV cm⁻², and a H₂O₂ yield of 229.33 μM after 6 h. To understand the mechanism of oxygen reduction reaction (ORR) in Ag-graphene-Cu systems, the electron transfer number for photocatalytic ORR and the surface facet of Ag NPs were studied. The Ag NPs in Ag-graphene-Cu systems with the deposition time of 180 s clearly shows that an amount of 〈200〉 facets are distributed on Ag nanoparticle surface, which can catalyze ORR by 2-electron pathway to generate H₂O₂ efficiently. This novel Ag-graphene-Cu nanosandwitch offers a new transfer path for hot-electrons and potentially provides a new concept for driving efficient solar energy to chemical energy.

构建了由银纳米粒子（Ag NPs）阵列，二维单层石墨烯（SG）和金属Cu接触制成的纳米三明治，利用太阳能在没有外部偏压的情况下生成过氧化氢（H ₂ O ₂）。Ag核心能级电子光谱中结合能向较低能的转移表明了Ag和石墨烯之间的强耦合，这可以通过内置电场有效地将热空穴从Ag转移到Cu，从而使热电子Ag上的NP直接用于引发H ₂ O ₂生成。该Ag-石墨烯-Cu纳米砂可以提供-15.8μAcm ^-2的稳定光电流，17.5 mV cm ^-2的稳定光伏电压。6小时后H ₂ O ₂产量为229.33μM。为了了解Ag-石墨烯-Cu体系中氧还原反应（ORR）的机理，研究了光催化ORR的电子转移数和Ag NPs的表面。沉积时间为180 s的Ag-石墨烯-Cu体系中的Ag NPs清楚地表明，大量的<200>刻面分布在Ag纳米颗粒表面，可以通过2电子途径催化ORR高效生成H ₂ O _2。。这种新颖的银-石墨烯-铜纳米夹层女巫为热电子提供了一条新的转移途径，并有可能为将有效的太阳能转化为化学能提供新的概念。