Tunable Kx-C3N4/ UiO-66-NH2 photocatalyst for selective oxidation of furfural to furoic acid with mediation of Na2CO3

Photocatalytic selective oxidation of furfural is a green, gentle way of preparing furoic acid. Photocatalytic oxidation effectively avoids the problems of difficult separation and high energy consumption in subsequent work-ups caused by the use of homogeneous oxidants. The photocatalytic process suffers from uncontrollable reactive oxygen species, resulting in low selectivity of the target product and excessive oxidation. Therefore, the K x -C 3 N 4 /UiO-66-NH 2 -Y catalyst was prepared by the mass proportion of UiO-66-NH 2 and K x -C 3 N 4 to form a heterogeneous structure, and the band gap width was adjusted to effectively avoid the formation of non-target strong reactive oxygen species ( OH). The results showed that: the aqueous 0.1 mM Na 2 CO 3 solution had an inhibitory effect on the non– target reactive oxygen species at room temperature; when the reaction time was 5 h and K 0.1 -C 3 N 4 /UiO-66-NH 2 -20, the furoic acid had the highest yield of 70.7, the target reactive oxygen species was confirmed by free radical capture experiments as O 2 – , and it was postulated that the reaction mechanism for the preparation of furoic acid by selective oxidation of furfural.