Photocatalytic water purification is an effective environmental protection approach for removing hazardous chemicals in water, besides solar energy conversion is a trustworthy and sustainable choice for the future due to rising energy demands. The present research focus is on synthesis of Metal-Organic Framework (MOF) based composite, Zeolitic Imidazolate Framework-67/Molybdenum Disulfide (ZIF-67/MoS2) entrenched Multi-Walled Carbon Nanotubes (MWCNT) as a catalyst for photodegradation of tetracycline (TC), as well as substitute for Pt counter electrode in Dye-Sensitized Solar Cell (DSSC). The crystalline structure, optical response, shape, porosity, quantum states, and chemical configuration were determined using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-DRS), Photoluminescence spectroscopy (PL), Transmission Electron Microscopy (TEM), Brunauer-Emmett-Teller (BET), and X-ray Photoelectron Spectroscopy (XPS), respectively. The degradation efficiency of ZIF-67/MoS2/MWCNT catalyst under effect of operational parameters namely, photocatalyst dosage, solution pH, coexisting ions, TC concentrations and irradiation time were studied consecutively. ZIF-67/MoS2/MWCNT composite achieved 96.1 % degradation efficiency of TC under white light irradiation. Interestingly, when utilized as a counter electrode in DSSCs, this composite-based electrode delivered the highest Power Conversion Efficiency (PCE) of 3.86 % with a short-circuit current density (JSC) of 7.54 mA cm−2 and open-circuit voltage (VOC) of 0.79 V. The observed enhancement is attributed to lesser peak-to-peak separation (EPP), lower electron lifetime, lower charge transfer resistance (RCT) and higher exchange current density (J0). Based on these findings, ZIF-67 inclusion in MoS2/MWCNT composite is not only an effective catalyst for water treatment but also a good catalyst for I3− reduction in DSSCs.