Hydrogen generation from methanolysis of sodium borohydride using waste coffee oil modified zinc oxide nanoparticles and their photocatalytic activities

Abstract

In this study, environmentally friendly zinc oxide nanoparticles (CO–ZnO NPs) were synthesized using coffee oil (CO) waste. The synthesized biogenic CO–ZnO NPs were analyzed by UV–Visible spectrometry (UV–Vis), Fourier-transformed infrared spectrum (FTIR), and X-ray diffraction (XRD) characterization methods. According to the UV–Vis spectrum, a double peak was observed at 281 nm and 323 nm in the waste coffee sample, and a single peak at 273 nm was observed for ZnO NPs. According to XRD analysis, the size of the ZnO NPs was determined as 16.37 nm. In the presence of Sodium borohydride (NaBH4) substrate, CO–ZnO NPs were observed to play a role as a catalyst with high activity in hydrogen production. According to the results obtained, Turnover of frequency (TOF), activation energy (Ea), enthalpy (ΔH), and entropy values (ΔS) were calculated as 805.17 s−1, 17.45 kJ/mol, 14.87 kJ/mol, −194.37 J/mol.K, respectively. In addition, it was determined that CO–ZnO NPs showed excellent photocatalytic activity. In photocatalytic measurements of the degradation of methylene blue (MB) dye under sunlight, it was observed that MB degraded by 96% and nanoparticles had high photocatalytic activity. This study aimed to synthesize a catalyst that can be used in the future as a high photocatalytic against pollutant wastewater and eco-friendly catalyst for hydrogen generation.