Organic substance-attached porous inorganic oxide particle

An organic substance-attached porous inorganic oxide particle comprising:

• a porous inorganic oxide particle;
• and
• an organic substance attached to a surface of the porous inorganic oxide particle,
• wherein the organic substance-attached porous inorganic oxide particle satisfies a formula below
• (Cf−Ce)/2>1
• where Cf represents the amount of carbon (atom %) measured by subjecting the surface of the particle to X-ray photoelectron spectroscopy (XPS) after the organic substance-attached porous inorganic oxide particle is washed, and Ce represents the amount of carbon (atom %) measured by subjecting the surface of the washed organic substance-attached porous inorganic oxide particle to X-ray photoelectron spectroscopy (XPS) after two-minute surface etching of the particle,
• wherein the organic substance-attached porous inorganic oxide particle is washed by mixing the organic substance-attached porous inorganic oxide particle with tetrahydrofuran (THF) to form a mixture, subjecting the mixture to a dispersion treatment, and centrifuging the mixture, followed by removing a supernatant to obtain the washed organic substance-attached porous inorganic oxide particle, and
• the washed organic substance-attached porous inorganic oxide particle is surface etched for two minutes by an argon monomer etching method using argon as an etching gas.