In this study, the mechanism of the effect of temperature, time, concentration, and Bi:S molar ratio on controlling the morphology of Bi2S3 particles synthesized by the hydrothermal method was evaluated. BiOCl and thiourea were used as sources of Bi and S ions, respectively. Synthesized particles were evaluated by XRD, SEM, ICP, BET, and TEM analysis. The kinetics of the process was evaluated using the Johnson- Mehl- Avrami equation. Photocatalytic properties were evaluated by measuring the UV spectra of MB solution. Also, the removal of Cr (VI) and As (V) was studied through adsorption on the Bi2S3. After optimizing the parameters, suitable conditions were determined (concentration: 1.5 mg/ml, Bi: S molar ratio: 1:2, temperature: 150 °C, and time: 25 h) for the synthesis of Bi2S3 with a self-assembled blade-shaped morphology with a high surface area (23.86 m2/g). This morphology showed a photocatalytic efficiency of 97 % for MB and removed 96.7 % of Cr (VI) and 89.3 % of As (V). Also, the results of the kinetic studies confirmed that the reaction mechanism is diffusion-controlled and the geometries are in the form of a plate.