Clean Production of 3,4-Dihydronaphthalen-1(2H)-one via the Photocatalytic Selective Oxidation of Tetraline: A High Value-Added Utilization of Naphthalene

Naphthalene, a major environmental pollutant, is generated in large quantities as a byproduct during the distillation of coal tar and petroleum in the energy chemical industry. Presently, the common harmless treatment of the chemical is to partially hydrogenate it into 1,2,3,4-tetrahydronaphthalene (tetraline), which is an industrial solvent. This work reports a novel technique that can further enhance the economic added value for naphthalene treatment, i.e., the photocatalytic selective oxidation of tetraline into 3,4-dihydronaphthalen-1(2H)-one. The reaction was performed under environment-friendly conditions using boron-doped polymer carbon nitride as a catalyst, affording a good product yield at 81%. The morphology, structure, and optical properties of the catalyst show that the synergistic effect of boron doping and nitrogen defects is the decisive reason for obtaining excellent photocatalytic performance.