Ya’ Muhammad Arsyad, et al. “Effect of TiO2 on Orange Peel Activated Carbon Composite in Reducing Carbon Monoxide and Hydrocarbon Gas Emissions”. JURNAL ILMU FISIKA | UNIVERSITAS ANDALAS, vol. 15, no. 2, Apr. 2023, pp. 73-80, doi:10.25077/jif.15.2.73-80.2023.