Construction of g-C₃N₄/MoS₂/SnO₂ hybrid as 2D/2D/1D architecture for counter electrode of dye-sensitized solar cells and photodegradation of pharmaceutical drugs from wastewater

In this work, we developed a heterogeneous g-C₃N₄/MoS₂/SnO₂ hybrid catalyst by a facile hydrothermal technique. A prepared hybrid was characterized and validated by XRD, FTIR and XPS. The BET analysis confirms that the surface area and pore volume values ​​of g-C₃N₄/MoS₂/SnO₂ (65.8 m² g^-1, 0.29 cm³ g^-1) are higher than those of g-C₃N₄. Further FE-SEM and HR-TEM analyses clearly show that self-assembled SnO₂ nanorods are randomly and freely dispersed in g-C₃N₄ and MoS₂ nanosheets as formed 2D/2D/1D nanostructure. The prepared hybrid served as counter electrodes (CE) for the fabrication of dye-sensitized solar cells (DSSC). The developed DSSC has J_sc, and V_oc parameter values of 8.6 mA/cm² and 0.558 V, then the resulting FF % and PCE % values were 0.7024 % and 3.38 %, respectively. The fabricated solar cells based on g-C₃N₄/MoS₂/SnO₂ hybrid maintain 90 % of PCE % after 15 days. The photocatalytic function of the produced samples was tested against the ciprofloxacin (CIP) and ibuprofen (IBU) pollutants degradation under UV–Vis light irradiation and the g-C₃N₄/MoS₂/SnO₂ hybrid catalyst showed higher photocatalytic degradation activity of 96 and 95 % towards CIP and IBU, respectively, which have higher efficiency than other synthesized samples within 80 and 100 min. The proposed photocatalytic mechanism of the constructed g-C₃N₄/MoS₂/SnO₂ hybrid system is based on 2D/2D/1D Z-scheme synergy, and further Z-scheme synergy was investigated by a scavenger test and ESR studies. The high charge separation efficiency in the photocatalyst is responsible for the improved degradation efficiency, which is achieved using g-C₃N₄ and SnO₂ as the reducing agents and MoS₂ as the co-catalyst and further studied its stability and reusability. This work effectively provides insight into the construction of a novel and extremely enforceable Z-scheme for UV–Vis light-based photocatalysts to degrade pharmaceutical pollutants from wastewater and low-cost energy harvesting for renewable energy.