Dyes are organic compounds used in textile, food and drug industries, and their abatement represents one of the main problems in the treatment processes because generally they are very stable toxic compounds. In this study, a novel sulfur, carbon and nitrogen triple doped-TiO 2 -CdS photocatalyst nanoparticles were embedded and deposited on polyethersulfone (PES) hollow fiber ultrafiltration membrane for degradation methyl orange. First, in order to accomplish solar-driven photocatalysis and low recombination rate of electron–hole pair, we employed a combinative method of trip doped TiO 2 in order to narrow the band gap of TiO 2 and CdS addition to suppress the recombination of electron-hole The carbon, nitrogen and sulfur (C, N and S) triple doped-TiO 2 -CdS nanoparticles as a hydrophilic and active photocatalyst modifier at low concentration in polymer matrix can degrade organic foulant on membrane surface under solar or visible light irradiation that decrease membrane fouling and finally increase permeation flux. In this work, two types of PES modi?ed membranes were prepared via entrapping and coating the membranes by modified TiO 2 nanoparticles. TiO 2 -entrapped PES membrane was prepared by addition of nanoparticles in the casting solution at different nanoparticle contents (1, 3 and 5 wt. %). The addition of C, N, S-tripledoped-TiO 2 -CdS nanoparticles into the polymeric casting solution have been developed porosity, morphology, structure, pure water flux (PWF), antifouling properties and separation performance of the embedded membranes due to hydrophilic behavior and photocatalytic properties of the C,N,S tripledoped-TiO 2 -CdS nanoparticles. The C, N, S-tripledoped-TiO 2 -CdS nanoparticles can be degraded adsorbed organic foulants on the membrane surface (reversible fouling) or deposited/trapped fouling agents into the membrane pores (irreversible fouling). Also, the interaction between organic foulant and hydrophilic membrane surface was prevented improving antifouling properties, wettability, and reusability of the modified membranes. The membrane with 3 wt. % of the C, N, S-tripledoped-TiO 2 -CdS nanoparticle has the highest pure water flux, flux recover ratio (FRR) and capability for dye removal (Dye removal was about 48.1 %). However, at high concentration of nanoparticles, agglomeration or aggregation of the nanoparticles on membrane surface/pores resulted in pore blocking, roughness membrane surface which led to slightly reduction of pure water flux, flux recover ratio (FRR) and separation performance. The obtained results were also confirmed by contact angle measurement, field emission scanning electron microscopy (FE-SEM), Energy-dispersive X-ray spectroscopy (EDAX). Visible light illumination improved the membrane performance and antifouling properties. For the second type, C, N, S-tripledoped-TiO 2 -CdS nanoparticles were coated on bare PES membrane surface. The prepared bare PES membrane was coated with C, N, S-tripledoped-TiO 2 -CdS by dipping the membrane in C, N, S-tripledoped-TiO 2 -CdS nanoparticle colloidal suspension and irradiated by UV light. This technique results in a superior membrane. The optimum conditions for preparation of C, N, S-tripledoped-TiO 2 -CdS nanoparticle coated membrane were determined as: 3 wt. % for concentration of nanoparticles colloidal suspension, 60 min immersion and 30 min UV. The prepared membranes were characterized by Fourier Transform Infrared Spectroscopy (FTIR-ATR). A comparison between coating and entrapped C, N, S-tripledoped-TiO 2 -CdS was also done and observed the membrane containing the coated photocatalyst with 55.3% dye removal was more ef?cient than the membrane containing the photocatalyst entrapped into the membrane.