chemical reactants / spray-coating technology / band gap energy / chemical detergents / lowest energy level / plastics / minimum energy / potential applications / so-called band gap energy / exterior applications / metal oxides / energy level / charge-carrier generation / sedimentation technology / band energy positions / air conditioning systems / paint chalking / photocatalytic active metal oxides / solar energy / chemical reaction / e-) / paint / industrial products / metal surface / building materials / chemical conversion / energy difference / activation energy / energy / outdoor applications / /