Abstract
Metal oxide nanoparticles prepared by biological route using green plant parts as a template are eco-friendly as well as yield good results than the conventional methods. This present study focusses on biosynthesis and characterization of TiO2 NPs using root extract of Kniphofia schemperi for dye-sensitized solar cells. TiO2 NPs were synthesized using 0.25 M titanium tetra butoxide in the presence of root extract of Kniphofia schemperi with the volume ratios. The analysis result revealed that the synthesized TiO2 NPs were thermally stable above 500°C and have spherical morphology, with the average crystalline size of 11.7, 8.3, and 8.6 nm, and band gap energy of 3.35 eV, 3.33 eV, and 3.36 eV, respectively, for the TiO2 NPs prepared at the volume ratios of 2 : 3, 1 : 1, and 3 : 2. Biosynthesized TiO2 NPs were used as photoanode in dye-sensitized solar cells (a device used for converting absorbed light into electricity). Solar cell devices were fabricated using roots of Kniphofia schemperi sensitizer in the presence of TiO2 NPs biosynthesized within (2 : 3, 1 : 1, and 3 : 2) volume ratio, which showed power conversion efficiency of 0.039%, 0.117%, and 1.3%. Incident photon to current conversion efficiency (IPCE) analysis using TiO2 (2 : 3, 1 : 1, and 3 : 2) photoelectrodes showed 6.64%, 2.66%, and 18%. Among the biosynthesized TiO2 different volume ratios, TiO2 (3 : 2) NPs showed relatively maximum solar cell efficiency and IPCE value due to its uniform spherical shape that enables to absorb large dye molecules on its surface, and this intern improves device efficiency.
Highlights
Energy exists in different forms from burning woods to obtain fire in prehistoric times to electricity productions in the modern age
The filtrate of the extract was used as a capping and reducing agent for the biosynthesis of TiO2 NPs within three different volume ratios
The extra peaks from the organic C and O bonds are attributed to a trace amount of extract pyrolytic residues left after a relatively lower temperature firing procedure. These results indicated that the presence of alcohols, phenols, primary amines, ketones, and aliphatic amines in the root extract of Kniphofia schemperi that have been participated in the process of synthesis of TiO2 NPs is responsible for the bioreduction of TiO(OH)2 to TiO2 NPs [30]
Summary
Energy exists in different forms from burning woods to obtain fire in prehistoric times to electricity productions in the modern age. Its consumption is one of the most important aspects in everyday life activities of human beings. The original sources of energy that peoples used to harvest have shown signs of deficiency due to the rapid growth in industrialization in many countries. Recent advances in solar energy conversion technologies based on organic semiconductors as light harvesting layer employ metallic oxide semiconductor (MOS) nanostructures for efficient charge extraction and transportation between the electrode and organic molecules [2]. Solar cells based on International Journal of Photoenergy dye-sensitized and porous nanocrystalline TiO2 photoanode with attractive performance were first reported in 1991 [3]
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