“…Focusing on solar technologies, in the last decade, DESs have been successfully exploited for the synthesis of active materials in thin film inorganic solar cells, such as active layers of CGS (CuGaSe 2 ) [ 65 , 66 ], CIS (CuInSe 2 ) [ 67 ], CIGS (Cu(In,Ga)Se 2 ) [ 68 , 69 , 70 , 71 ], and CZTS (Cu 2 ZnSnS 4 ) [ 72 ]. A perusal of the recent literature has shown that DESs have also been successfully employed in the synthesis of active materials for water splitting, in particular to be applied in photocatalytic [ 73 ] or photoelectrochemical [ 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 ] setup, or both [ 82 , 83 ].…”