Preparation and characterization of bonded silica hydride intermediate from triethoxysilane and dimethylmethoxysilane using supercritical carbon dioxide and dioxane as reaction medium

► Silica hydrides were prepared in sc-CO2 and dioxane as reaction solvents. ► Efficient modification of SiH with sc-CO2 compared to organic solvents. ► 4.46 μmol/m2 (TES), 3.39 μmol/m2 (DMMS) in sc-CO2, 0.69 μmol/m2, 2.66 μmol/m2 in dioxane. ► 84.4% efficiency of SiH (TES), 42.4% (DMMS) in sc-CO2 and 33.3% (DMMS) dioxane. ► sc-CO2 generated SiH (TES) revealed two IR, υSiH bands at 2283 cm−1 and 2250 cm−1.