One-pot synthesis of BaO/Graphene nanocomposites for photo-electrocatalysis degradation of organic dye: A novel approach and nanocomposite performance assessment

Pure cubic BaO and BaO/graphene nanocomposite were fabricated via a simple auto-combustion method. The structural characteristics of prepared nanocomposite were investigated using XRD, FT-IR, SEM, HR-TEM, EDX, BET, and UV–Vis DRS analytical techniques. XRD data revealed the nanocomposite's tetragonal crystal structure, characteristic of highly crystalline BaO. SEM and HR-TEM showed a quasi-spherical shape decorated on a graphene sheet. BET was utilized to estimate the surface area of BaO/G-3, which was found to be 1.4912 m².g⁻¹. For pure BaO and BaO/G-3 NCs, energy band gap (E_g) drops from 3.956 eV to 3.875 eV, respectively. Methylene blue degradation was demonstrated by BaO and BaO/G NCs. MB dye was degraded via two favorable technologies: electrocatalysis and photo-electrocatalytic oxidation. Results revealed that BaO/G-3 NCs catalyst achieved 97.1 % and 98.7 % degradation of MB dye within 25 min and 15 min for electrocatalysis and photo-electrocatalytic degradation, respectively. BaO/G ratio, temperature, solvent molarities, the concentration of the supporting electrolyte (NaCl), pH, and electrical potential are some synthetic and operational factors studied to determine PEC degradation process. Radical scavengers' effects on BaO/G-3 show that ^•OH is responsible for MB degradation. After five cycles, degradation of approximately 93 % was confirmed, indicating the material's viability for the treatment of PEC wastewater.