A facile chemical synthesis of nanoflake NiS(2) layers and their photocatalytic activity

A single-phase and crystalline NiS(2) nanoflake layer was produced by a facile and novel approach consisting of a two-step growth process. First, a Ni(OH)(2) layer was synthesized by a chemical bath deposition approach using a nickel precursor and ammonia as the starting solution. In a second step, the obtained Ni(OH)(2) layer was transformed into a NiS(2) layer by a sulfurization process at 450 °C for 1 h. The XRD analysis showed a single-phase NiS(2) layer with no additional peaks related to any secondary phases. Raman and X-ray photoelectron spectroscopy further confirmed the formation of a single-phase NiS(2) layer. SEM revealed that the NiS(2) layer consisted of overlapping nanoflakes. The optical bandgap of the NiS(2) layer was evaluated with the Kubelka–Munk function from the diffuse reflectance spectrum (DRS) and was estimated to be around 1.19 eV, making NiS(2) suitable for the photodegradation of organic pollutants under solar light. The NiS(2) nanoflake layer showed photocatalytic activity for the degradation of phenol under solar irradiation at natural pH 6. The NiS(2) nanoflake layer exhibited good solar light photocatalytic activity in the photodegradation of phenol as a model organic pollutant.