Preparation of a La(OH)CO3/NiAl-LDHs interface junction photoinitiated activator: Excellent photoinitiated activity and the photoactive pathway for destruction of phenol in wastewater

s The development of a new type of photocatalyst for multiple deep degradation of phenol in wastewater together with the elucidation of the method for this process are highly significant in the treatment of sewage. In this report, three-dimensional heterostructured La(OH)CO 3 /NiAl-LDHs composite catalysts were prepared by loading ultrathin NiAl-LDHs onto La(OH)CO 3 substrates using a hydrothermal synthesis method and an in-situ growth technique. Photocatalytic experimental studies showed that La(OH)CO 3 /NiAl-LDHs could remove up to 97 % of (degrade) phenol from water, which was 5.86 and nearly two-fold greater than pure NiAl-LDHs and La(OH)CO 3 . Even after 5 cycles, La(OH)CO 3 /NiAl-LDHs still sustains an excellent photocatalytic stability (93.6 % phenol degradation). Fabrication of ultrathin NiAl-LDHs greatly enhanced the surface expanse of the composites from 1.442 m 2 /g to 140.16 m 2 /g, exposing more active sites. According to the in-situ XPS analysis under irradiation and the capture of active species on La(OH)CO 3 /NiAl-LDHs, the electrons would be transferred from La(OH)CO 3 to ultrathin NiAl-LDHs. The S-type heterointerfaces formed at the La(OH)CO 3 substrate with ultrathin NiAl-LDHs nanosheets effectively inhibited carrier complexation and improved the catalytic performance. Meanwhile, the formation of oxygen vacancies between La(OH)CO 3 and NiAl-LDHs further enhanced the photocatalytic activity. The photocatalytic degradation mechanism of phenol showed that the main radicals of this catalytic reaction were •O 2 - and •OH. The three-dimensional stratified staging engaged with La(OH)CO 3 and the ultrathin NiAl-LDHs mixed nanosheet faces offered a new path to advance superlative catalysts to treat sewage.