Binary intrinsic defects in two-dimensional molybdenum disulfide toward detection mechanism of 2,4,4′-trichlorobiphenyl

Structure defects of advanced two-dimensional (2D) transition metal dichalcogenides (TMDCs) have provided enormous opportunities for modified band structures and fascinating properties to facilitate the development of fundamental studies, among which intrinsic defects can be spontaneously introduced to 2D materials to expand the functional diversity. Except for unary intrinsic defects, structure–activity relationships of multiplex intrinsic defects and modulated properties still remain to be released for practical applications. Herein, binary intrinsic defects in exfoliated molybdenum disulfide (MoS 2 ), including sulfur monovacancies and oxygen substitution, were studied for revealing the sensing mechanism of 2,4,4′-trichlorobiphenyl (PCB28). They theoretically tended to form homosteric associated pairs and promote molecular anchoring synergistically. Appropriate molecular adsorption and efficient electron transfer enabled the excellent sensing performances for PCB28 including considerable linear region of 100 ng mL −1  ∼ 1 mg mL −1 and low detection limit of 7.96 ng mL −1 , which was also inspirable for the design of other small-molecule sensors.