In this study, we report the vertically aligned ZnO nanowalls (NWs) decorated electrochemically reduced graphene oxide (ERGO) structures co-deposited directly on the FTO substrates by a simple and one-pot electrochemical technique. Then, these ERGO/ZnONWs were co-sensitized with a successive layer of PbS and CdS quantum dots (QDs) by a successive ionic layer adsorption and reaction (SILAR) technique for the fabrication of ERGO/ZnONWs/PbS/CdS photoelectrodes. The effect of the number of PbS and CdS SILAR cycles on the photocurrent response of ERGO/ZnONWs photoelectrodes was systematically investigated by varying the SILAR cycle number. The QDSSCs were fabricated by using the PbS, CdS and PbS/CdS QDs decorated ERGO/ZnONWs as photoelectrode, copper (I) sulfide (Cu₂S) as the counter electrode, and polysulfide redox couple (S²⁻/S_x²⁻) as an electrolyte. Compared with ERGO/ZnONWs photoelectrode sensitized with single QDs (PbS or CdS), the PbS/CdS co-sensitized ERGO/ZnONWs photoelectrodes showed the best performance with efficiency (η) of 5.85%, open-circuit voltage (V_oc) of 0.65V, a short circuit current density (J_sc) of 23.01 mA.cm⁻², and a fill factor (FF) of 0.39 under one sun illumination, which is relatively higher than other PbS/CdS co-sensitized ZnO based QDSSCs previously reported in the literature. In this cascaded FTO-ERGO/ZnONWs/PbS/CdS, CdS serves as a passivating layer to PbS and contributes light absorption and highly efficient injection of electrons from CdS to PbS and then to ZnO due to its higher CB band. The present study also highlights the potential of this novel ERGO/ZnONWs/PbS/CdS photoanode. It introduces simple, green, and economical electrochemical techniques for researchers interested in fabricating ERGO/ZnONWs for various applications.

在这项研究中，我们报告了垂直排列的 ZnO 纳米墙 (NW) 装饰的电化学还原氧化石墨烯 (ERGO) 结构通过简单的单锅电化学技术直接共沉积在 FTO 基板上。然后，这些 ERGO/ZnONWs 通过连续离子层吸附和反应 (SILAR) 技术与连续的 PbS 和 CdS 量子点 (QD) 层共同敏化，用于制造 ERGO/ZnONWs/PbS​​/CdS 光电极。通过改变 SILAR 循环数，系统地研究了 PbS 和 CdS SILAR 循环数对 ERGO/ZnONWs 光电极光电流响应的影响。QDSSCs 是以 PbS、CdS 和 PbS/CdS QDs 修饰的 ERGO/ZnONWs 为光电极、硫化铜 (I) (Cu ₂S)作为对电极，多硫化物氧化还原对(S ^2- /S _x ^2- )作为电解质。与单量子点（PbS或CdS）敏化的ERGO/ZnONWs光电极相比，PbS/CdS共敏化的ERGO/ZnONWs光电极表现出最佳性能，效率（η）为5.85%，开路电压（V _oc）为0.65 V、 23.01 mA.cm ^-2的短路电流密度 ( J _sc )和填充因子 ( FF)在一个太阳光照射下为0.39，这相对高于先前文献报道的其他PbS/CdS共敏化ZnO基QDSSCs。在这种级联的 FTO-ERGO/ZnONWs/PbS​​/CdS 中，CdS 用作 PbS 的钝化层，并且由于其较高的 CB 带，有助于光吸收和电子从 CdS 到 PbS 再到 ZnO 的高效注入。本研究还强调了这种新型 ERGO/ZnONWs/PbS​​/CdS 光电阳极的潜力。它为有兴趣为各种应用制造 ERGO/ZnONW 的研究人员介绍了简单、绿色和经济的电化学技术。