“…Typically, the combination of SnO 2 and TiO 2 can be classified into two categories: (a) SnO 2 and TiO 2 particles separate from each other to form a layer–layer − ,, or core–shell structure; − (b) SnO 2 and TiO 2 particles mix with each other to be a rather homogeneous structure. ,, For the second style, due to the high hydrolysis rate of titanium alkoxides, most of the SnO 2 –TiO 2 syntheses start from sol solutions followed by gelation, solvothermal reaction, thermal decomposition, or precipitation . In the gelation and particle formation processes, SnO 2 and TiO 2 can undergo separation processes because of different hydrolysis and condensation rates of titanium and tin precursors. ,, Besides the adoption of a chelating agent or control of the pH value to slow down the hydrolysis rate of the titanium precursor, it has been proposed that using single-source precursors with two different metal atoms in one molecule can significantly avoid phase separation or improve the dispersion of two metals, resulting in mixed metal oxides with high dispersion . Single-source precursors can have different compositions: (1) in the form of M–L–B–L′–M′, , where M and M′ are connected by an “amphiphilic” ligand L–B–L′; (2) in the form of M–O–M′ or M−μOR–M′, where M and M′ atoms are connected by an oxygen atom or an alkoxo group.…”