A highly porous MgO entrenched MWCNT composite as a low-cost Pt-free counter electrode for dye-sensitized solar cells and visible light photocatalytic performance towards Congo-red

Nanostructured composite photocatalysts, consist of multi-walled carbon nanotubes (MWCNT), and cubic face magnesium oxide (MgO) were prepared by sol-gel methodology. Powder X-ray powder diffraction (PXRD) results reveals that the sample was composed of CNT and cubic MgO. Field emission scanning electron microscope (FESEM) studies showed that multi-walled CNTs with the outer diameters of 20-25 nm and length up to several micrometers, which were uniformly coated with the disc like nanoparticles whose diameter was in the range of 20-30 nm. The optical absorption edge was shifted to longer wavelength for MgO/MWCNTs composite, which is confirmed through UV-vis diffuse reflectance (DRS) analysis. The prepared MgO-MWCNTs composite proficiently catalyzed the photodegradation of phenol and congo-red under visible light irradiation. After seven trials, just 3.5 % of the photocatalytic efficiency of the MgO/MWCNTs composite was lost to congo-red, which is an excellent result. We go into great detail about the potential photocatalytic pathway as well. When used in a photovoltaic device, the MgO/MWCNT CE showed high PCE of 5.15% with long term stability. The EIS results also prove that lower resistance and high electron life time. [GRAPHICS] .

Automated summary

Nanostructured composite photocatalysts consisting of MWCNT and cubic MgO were prepared using sol-gel methodology. The composite exhibited effective catalysis for the photodegradation of phenol and congo-red under visible light irradiation. It also showed high PCE and long-term stability when used in a photovoltaic device.