Sb2S3 entrenched MWCNT composite as a low-cost Pt-free counter electrode for dye-sensitized solar cell and a viewpoint for a photo-powered energy system

•The capacitive and photovoltaic performance of MWCNT/Sb2S3 is counter electrode is presented.•The new electrode exhibits an efficiency of 5.02% with a short circuit current of 12.68 mA cm−2.•Electrocatalytic activity and EIS data supports excellent counter electrode performance.•Supercapacitor shows the highest capacity of 228 C g−1 and capacitance retention of 92.5%.•Sb2S3/MWCNT hybrids offer a potential material for photo-powered energy system development. The current research interest is to use Sb2S3 entrenched Multi-Walled Carbon Nanotubes (MWCNT) composite as Pt-free counter electrode in dye-sensitized solar cells (DSSCs) and also to test its usage as a supercapacitor. Hence here, Sb2S3 nanorods with different concentrations of MWCNT have been synthesized by facile microwave irradiation technique and are used as a counter electrode in Pt-free DSSCs and also tested for supercapacitance. Crystalline structure, shape, and quantum states have been elucidated using XRD, TEM, and XPS spectra, respectively. Among all, Sb2S3/CNT30 composite counter electrode delivers the highest Power Conversion Efficiency (PCE) of 5.02% with a short circuit current (JSC) of 12.68 mA cm−2 and open-circuit voltage (VOC) of 0.68 V. The improvement observed is due to the lower peak-to-peak separation (Epp), higher exchange current density (J0) and lower charge transfer resistance (RCT). The obtained PCE is compared with the standard Pt-based counter electrode (PCE~5.8%) and discussed. This composite is also found to be a suitable material for the supercapacitor. Among the electrodes, Sb2S3/CNT100 exhibits the highest specific capacity of 228 C g−1 with 1 Ag−1 with the capacitive retention of ~92.5% over 1000 charge-discharge cycles, which also reveals its ability for energy storage. The excellent capacitive and photovoltaic output highlights the promise of Sb2S3/MWCNT for photo-supercapacitor devices. [Display omitted]