We demonstrate the CsPbBr₃ nanoparticles can in-situ growth on semiconducting graphene oxide (GO) and conductive few-layer graphene (FLG) surfaces, individually. The type-II and Schottky-junction-like energy band structures of CsPbBr₃-GO and CsPbBr₃-FLG nanoheterostructures (NHSs) resulted in the varied interfacial charge transfer (CT) behaviors. The CT rate constant (k_CT) of CsPbBr₃-GO and CsPbBr₃-FLG NHSs could be modulated by controlling their constituent ratio of GO/FLG. Moreover, the CO₂−to−CH₄ conversion rate ($k_{{\text{C}\text{H}}_4}$) of CsPbBr₃-GO NHSs showed a positive relation with k_CT, while the negative correlation between $k_{{\text{C}\text{H}}_4}$ and k_CT for CsPbBr₃-FLG NHSs was observed. The mechanism can be suggested as that the different energy band structures in CsPbBr₃-graphehe-based NHSs provide the varied reduction potential for the photoexcited charge carriers to effect the performance in photocatalytic CO₂ reduction. This work presents the important insights into the design of perovskite-graphene based NHS with remarkable performance for solar-driven CO₂ conversion.

我们证明了CsPbBr ₃纳米颗粒可以分别在半导体氧化石墨烯（GO）和导电性几层石墨烯（FLG）表面上原位生长。CsPbBr ₃ -GO和CsPbBr ₃ -FLG纳米异质结构（NHSs）的II型和肖特基结状能带结构导致不同的界面电荷转移（CT）行为。CsPbBr ₃ -GO和CsPbBr ₃ -FLG NHS的CT速率常数（k _CT）可以通过控制GO / FLG的组成比来调节。此外，CO ₂到CH _4的转化率（${ķ}_{{\text{C}\text{H}}_4}$）的CsPbBr ₃ -GO NHS与k _CT呈正相关，而两者之间呈负相关${ķ}_{{\text{C}\text{H}}_4}$和ķ _CT为CsPbBr ₃观察-FLG NHS的。可以提出该机理，因为基于CsPbBr _3-石墨烯的NHS中不同的能带结构为光激发电荷载流子提供了变化的还原电位，从而影响了光催化CO ₂还原的性能。这项工作为基于钙钛矿-石墨烯的NHS设计提供了重要见识，该设计具有出色的太阳能驱动的CO ₂转化性能。