Agave Bagasse as an Eco-Friendly Template for the Microwave-Assisted Synthesis of C@TiO2 Photoelectrodes

This work reports, for the first time, the use of agave bagasse from “Tequila Weber Var” as an efficient and eco-friendly template for the microwave-assisted solvothermal synthesis of C@TiO2 photoelectrodes. The characterization of the C@TiO2 materials was performed using composition and elemental analysis, diffuse reflectance/UV-visible spectroscopy, N2 adsorption/desorption isotherms, scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction patterns, cyclic voltammetry, impedance spectroscopy, and variations of the open-circuit potential in a conventional electrochemical cell. Three 1:1, 4:1, and 8:1 agave:Ti volume ratios were used to explore the influence of carbon content upon the optical and photoelectric properties of TiO2. The composite with a 1:1 ratio showed a charge transfer kinetic capacity of 0.86 C·cm−2·s−1 with the highest current density flow of 2.2 mA·cm−2, and the lowest optical band gap (Ebg) value of 2.92 eV, boosting the optoelectronic behavior of TiO2. The photoanode composed of FTO/C@TiO2 with the hybrid material with a 1:1 ratio was preliminarily evaluated in a photovoltaic solar cell, showing a light-to-electricity conversion efficiency higher than the other two composites and up to 12.5 times higher than the photoanode only composed of neat TiO2. The present results contribute to the state-of-the-art of eco-friendly organic–inorganic thin film photoelectrodes for the sustainable synthesis of third-generation solar cells using bagasse-derived waste as an efficient carbon source for the synthesis of hybrid photoactive semiconductors.