Article including porous layer containing inorganic particles, and coating liquid for forming porous layer containing inorganic particles

An article, comprising:

• a substrate;
• and
• a porous layer disposed over the substrate, the porous layer containing inorganic particles bound by an inorganic binder,
• wherein the inorganic particles include chain-like particles and particles other than the chain-like particles, and a volume fraction of the chain-like particles is 55% or more and 95% or less based on the inorganic particles,
• wherein the porous layer has a film thickness of 1,000 nm or more and 5,000 nm or less, and
• wherein the particles other than the chain-like particles have an average particle diameter of 10 nm or more and 300 nm or less, and
• wherein a difference between a refractive index of a region of the porous layer extending from a position of half of a film thickness of the porous layer to a side of the porous layer adjacent to the substrate and a refractive index of a region of the porous layer extending from the position of half of the film thickness of the porous layer to a side of the porous layer remote from the substrate is 0.01 or less.