Abstract: Recent advances in visible-light-responsive photocatalysts allow for the creation of novel and efficient solar energy conversion technologies. It is possible to oxidize or reduce materials, generate products such as H2, or degrade organic pollutants from wastewater; thus, photocatalytic technologies could contribute to the solution of two current challenges facing the world today: providing clean energy, and protecting the environment and natural resources. TiO2 is the most widely used photocatalyst due to its high chemical stability, high photoreactivity and low cost. It is typically suspended in a treated aqueous solution, forming a slurry, where mass transfer between the catalyst and the reagents is improved via mechanical stirring. In these processes, the recovery of the catalyst becomes difficult; the solid must be separated from the treated water for further reuse. Since the conventional coagulation–sedimentation method, more effective designs have been developed based on the use of membranes either by designing hybrid processes that combine photocatalysis with membrane filtration (PMF) or allowing the photocatalytic and separation processes to occur in a single step (PMR). These alternatives overcome many of the difficulties that are associated with catalyst separation and recovery and promote process intensification (PI). This paper presents a critical review of photocatalytic processes that incorporate membranes, PMF and PMR, highlighting each process’ advantages and drawbacks as well as identifying the corresponding intensification indices and forecasting future prospects.

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