NOVELTY - Making coated article including broadband anti-reflective coating (3) comprising porous silica disposed, directly or indirectly, on a glass substrate (1), comprises: forming coating, directly or indirectly, on glass substrate by disposing on glass substrate a coating solution formed from silane, mesoporous silica nanoparticles, and solvent; and drying coating and/or allowing coating to dry so as to form anti-reflective coating comprising nonporous silica and mesoporous silica nanoparticle based matrix on glass substrate, where coating includes porosity defined by first and second pore sizes.    USE - The method is useful for making coated article including broadband anti-reflective coating (claimed), where the coated article are used as windows, and in lighting applications, in handheld electronic devices, display devices, display cases, monitors, screens, TVs, photovoltaic devices, greenhouses, storefront windows, solar cells and picture frames.    ADVANTAGE - The method provides coated article including broadband anti-reflective coating that effectively reduce the reflection of visible light; and utilizes porous nanoparticles with small pores, thus increasing the durability of the coating.    DETAILED DESCRIPTION - Making a coated article including a broadband anti-reflective coating (3) comprising porous silica disposed, directly or indirectly, on a glass substrate (1), comprises: forming a coating, directly or indirectly, on the glass substrate by disposing on the glass substrate a coating solution formed from a silane, mesoporous silica nanoparticles comprising at least one functional group, and a solvent; and drying the coating and/or allowing the coating to dry so as to form an anti-reflective coating comprising a nonporous silica and mesoporous silica nanoparticle based matrix on the glass substrate, where the coating includes a porosity defined by first and second pore sizes, the first pore size is created as a result of a geometric package of mesoporous silica nanoparticles and metal oxide particles in the matrix, and the second pore size is created by virtue of a pore size of the mesoporous silica nanoparticles. INDEPENDENT CLAIMS are also included for:    (1) making an anti-reflective coating, comprising: providing a coating solution comprising at least a metal oxide, porous nanoparticles, and the solvent; disposing the coating solution on a glass substrate so as to form a coating comprising a metal oxide and porous nanoparticle-based matrix; and drying and/or heat treating the substrate with the coating on it, so as to form a coating comprising a porous metal oxide;    (2) a coated article comprising either: a glass substrate, and the coating supported by the glass substrate, where the coating comprises a matrix comprising mesoporous silica nanoparticles and silica; or a glass substrate with an anti-reflective coating disposed on it, where the anti-reflective coating comprises porous nanoparticles and silica; and    (3) making a coated article including anti-reflective coating comprising porous silica, directly indirectly, on a glass substrate, comprising: forming a coating solution comprising a silane, porous nanoparticles, and a solvent; forming a coating, directly or indirectly, on the glass substrate by disposing the coating solution on the glass substrate; and drying the coating and/or allowing the coating to dry so as to form a coating comprising silica and a matrix comprising the porous nanoparticles on the glass substrate, so as to form an anti-reflective coating comprising a silica-based matrix on the glass substrate.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of a single-layered anti-reflective coating.    Glass substrate (1)    Anti-reflective coating (3)