Photocatalytic Water Disinfection Research Articles

Efficient water disinfection accelerated by polymerization-degree-controlled graphitic carbon nitride under visible light

In the quest for continuously raising the quality of drinking water, the exploration for effective photocatalysts to facilitate photocatalytic water disinfection remains an enduring challenge. Here, we demonstrate that by easily adjusting the polymerization degree of graphitic carbon nitride (g-C3N4), g-C3N4 itself can attain an exceptional photoactivity for disinfecting various waterborne bacteria. By synergistically integrating experimental investigations with density functional theory calculations, we propose that fine-tuning the polymerization degree of g-C3N4 confers remarkable attributes conducive to the specific generation of H2O2 through a two-electron reduction pathway. This ultimately culminates in the attainment of efficient water disinfection, that 7-log reduction in E. coli concentration is achieved within 180 min, in the absence of any additional cocatalyst. This work may shed light on developing highly efficient g-C3N4-based photocatalytic disinfectants for water disinfection applications.

Construction of the Z-scheme Cu2O-Ag/AgBr heterostructures to enhance the visible-light-driven photocatalytic water disinfection and antibacterial performance

Constructing Z-scheme heterojunctions is considered to be an excellent strategy for enhancing the photocatalytic performance of compounds. In this study, visible-light-driven (VLD) Z-scheme Cu2O-Ag/AgBr photocatalysts with high efficiency were constructed with the aid of a photo-reduction precipitation technique. The photocatalytic properties and different mass fractions of Ag/AgBr nanoparticles were in situ deposited on the surface of an octahedral Cu2O. The results indicated that nearly 98.7% methyl orange (MO) could be degraded within 90 min using Cu2O-Ag/AgBr. Due to the reactive oxygen species (ROS) generated by Cu2O-Ag/AgBr, 99% antibacterial efficiency was achieved by Cu2O-Ag/AgBr against Gram-positive/Gram-negative bacteria. After four consecutive cycles of Cu2O-Ag/AgBr, the photocatalyst remained relatively stable and exhibited excellent stability and reusability. Various analyses demonstrated loading Ag/AgBr nanoparticles into composites can enhance their optical properties, accelerating the transport of photogenerated carriers. The Z-scheme heterojunction between Ag/AgBr and Cu2O provided higher redox capability. Moreover, the photocatalytic properties of the composites can be boosted via the surface plasmon resonance (SPR) effect from a small amount of metallic Ag. Lastly, the mechanism of photocatalysis occurrence was elucidated by exploring the essential reaction substances in the process, and primary active species were discovered to be the photogenerated holes (h+), •O2‾, and •OH. This study indicated that the as-prepared Cu2O-Ag/AgBr exhibited great potential to be applied in wastewater treatment.

Using Cell Motility and Particle Tracking to Deduce Mechanisms and Kinetics Underlying Photocatalytic Water Disinfection in Real Time

Photocatalysis is a promising water disinfection method that has the potential to complement traditional approaches to water remediation. Large-scale implementation of photocatalysis for water remediation requires a two-fold improvement to the current state-of-the-art: understanding of the mechanisms underlying photocatalyst-pathogen interaction and pathogen inactivation during photocatalysis, and a process for rapid catalyst discovery that provides for evaluating photocatalyst efficacies in a reliable manner. Toward this goal, we will discuss the use of novel tools developed in our laboratory to track the viability loss of bacterial cells inactivated by photocatalytic treatment in real time. Using optical microscopy and particle-tracking algorithms, we observed that, when exposed to titanium dioxide (TiO2) nanowire-assisted photocatalytic stressors, the change in the motility of Escherichia coli (E. coli) cells tracks viability loss precisely. Furthermore, using phase and fluorescence optical microscopy, real-time observations of the interactions between the cells and the photocatalyst nanowires were also performed. Our findings suggest that these interactions occur through collisions between the nanowires and bacteria. Based on these observations, we developed a phenomenological model explaining the pseudo-first-order kinetics of E. coli inactivation. Through the use of fluorescence-based microscopy, we observed that the motility loss (and hence viability loss) was due to the dissipation of the proton motive force that powers motility, caused by cell membrane integrity loss. Our experiments show a good match between the kinetics of motility loss and viability loss for various operating conditions, showing that the methods presented here are versatile in applicability. Overall, our results indicate that these in situ methods offer significant time-savings for characterizing viability loss of pathogens over the traditional ex-situ methods. As indicated above, these methods will also help accelerate the evaluation of novel antibacterial agents, including, but not limited to novel photocatalysts, against emerging treatment-resistant pathogens, for applications ranging from water disinfection to equipment decontamination in healthcare facilities.

Independent and simultaneous photocatalytic decontamination and disinfection of water over In2O3/TiO2 heterojunctions

We have explored the application of In2O3/TiO2 heterojunctions to the photocatalytic removal of a substance classified as a pollutant of emerging concern, such as the anti-inflammatory drug sodium diclofenac (DCF), from aqueous solutions. In addition, the study of water disinfection by means of photocatalysis, simultaneously with the elimination of DCF, has been carried out with the same catalysts, by using bacterial populations of the genus Enterococcus faecalis. The In2O3/TiO2 catalysts with different indium amounts consist of bi-phasic samples with anatase TiO2 and In2O3 phases, without evidence in In doping into the titania structure, and show, according to UV–vis and time-resolved fluorescence spectra, light absorption into the visible range and interfacial charge transfer from the conduction band of In2O3 to that of TiO2. Complete photocatalytic removal of DCF was achieved by using all catalysts after 120 min of irradiation, being the most active the catalyst with 5% of In2O3, in agreement with its highest efficiency of interfacial charge transfer revealed by fluorescence lifetime. In contrast, in terms of DCF mineralization, the 5In2O3/TiO2 catalyst did not outperform the pristine TiO2, the higher mineralization percentage being achieved with 1% In. Simultaneous decontamination and disinfection experiments show that the 5% In2O3/TiO2 heterojunction outperforms the activity of titania for DFC removal in the presence of Enterococcus faecalis, but not for the inactivation of bacteria.

Real-Time Deduction of Mechanisms and Kinetics Underlying Photocatalytic Water Disinfection: Cell Motility and Particle Tracking.

The current methods used to study photocatalysis-assisted water disinfection at a laboratory scale may not lead to process scale-up for large-scale implementation. These methods do not capture the process complexity and address all the factors underlying disinfection kinetics, including the physical characteristics (e.g., shape and size) of the photocatalyst, the light intensity, the form of the catalyst (e.g., free-floating and immobilized), and the photocatalyst-microorganism interaction mode (e.g., collision mode and constant contact mode). This drawback can be overcome using in situ methods to track the interaction between the photocatalysts and the microorganisms (e.g., Escherichia coli) and thereby engineering the resulting disinfection kinetics. Contextually, this study employed microscopy and particle-tracking algorithms to quantify in situ cell motility of E. coli undergoing titanium dioxide (TiO2) nanowire-assisted photocatalysis, which was observed to correlate with cell viability closely. This experimentation also informed that the E. coli bacterium interacted with the photocatalysts through collisions (without sustained contact), which allowed for phenomenological modeling of the observed first-order kinetics of E. coli inactivation. Addition of fluorescent-tagging assays to microscopy revealed that cell membrane integrity loss is the primary mode of bacterial inactivation. This methodology is independent of the microorganism or the photocatalyst type and hence is expected to be beneficial for engineering disinfection kinetics.

A new magnetic-hybrid photoreactor for photocatalytic water disinfection

A new magnetic-hybrid photoreactor for photocatalytic water disinfection

Ternary rGO decorated W18O49 @g-C3N4 composite as a full-spectrum-responded Z-scheme photocatalyst for efficient photocatalytic H2O2 production and water disinfection

Integrating g-C3N4 with narrow-band semiconductor to construct a Z-scheme structured heterojunction has been regarded as a common strategy to improve the photocatalytic performance of g-C3N4. However, limited catalytic activity increment is achieved due to the contradiction of expanding the light absorption scope of traditional photo-oxidation semiconductors (PS II) and preserving their valance band oxidative abilities. Herein, to extend the light absorption range of g-C3N4 based Z-scheme photocatalyst to the whole solar spectra while without losing the high oxidative ability of this system, we select the heavy doped W18O49 as PS II and provide a facile in situ hydrothermal method to elaborately fabricate an rGO decorated W18O49 @g-C3N4 (r-CNW) Z-scheme photocatalyst. The prepared r-CNW-2 (with optimal W18O49 to g-C3N4 weight ratio of 1:2) exhibits improved photocatalytic performance with H2O2 generation rates of 71, 58.5 and 6.3 μmol g−1 h−1 obtained under the simulated solar light, visible light (>400 nm) and NIR light (>800 nm) irradiation, respectively, which is 1.3 and 2 times higher than those of the g-C3N4 counterparts (54, 29 μmol g−1 h−1 and even not detected).such outstanding performance of r-CNW-2 could be associated with the broader light absorption, fast charge separation, and rapid redox reactions. Moreover, the r-CNW-2 also displays an excellent E-coli inactivation activity, comparable to most g-C3N4-based photocatalysts. Our work gives a new insight through trading off light absorption and redox ability to fabricate efficient Z-scheme photocatalyst for photocatalytic H2O2 generation and environmental remediation.

Efficient photocatalytic water disinfection by a novel BP/BiOBr S-scheme heterojunction photocatalyst

With the ever-growing threat posed by pathogenic microorganisms, the development of high-performance photocatalysts for energy-efficient and rapid water disinfection is urgently required. In this study, an S-scheme heterojunction involving black phosphorus (BP) and bismuth oxybromide (BiOBr) is designed by a facile exfoliation strategy. The BP/BiOBr with 0.75% of BP (0.75 %BP/BiOBr) exhibits an outstanding photocatalytic disinfection activity, with the total 7 log killing of E. coli cells in only 7.5 min under visible-light illumination, which is 2 times higher than that of pure BiOBr. And the similar performance was observed for the tap water and river water under real sunlight. The enhanced disinfection efficiency of BP/BiOBr arises from the high yield of the ·O2− and ·OH resulting from the formation of S-scheme heterojunction. Then the ·O2− and ·OH damaged the cell membrane of the bacterial, leading to their death finally. This research sheds lights on the design and application of S-scheme heterojunction photocatalysts in water disinfection.

Magnetic carbon nanotubes/red phosphorus/graphitic carbon nitride heterojunction for highly efficient visible-light photocatalytic water disinfection

The development of recyclable antimicrobial catalysts with high photocatalytic disinfection efficiency is urgently needed. To this end, a ternary heterojunction of magnetic carbon nanotubes/red phosphorus/graphitic carbon nitride (MCNTs/RP/CN) is designed and applied as a recyclable photocatalytic disinfectant for the first time. Significantly, the MCNTs/RP/CN outperforms the most-studied P25 TiO2 under both visible-light and real-sunlight illumination, and its disinfection efficiency ranks as one of the best among various CN-based catalysts developed previously. The bacterial inactivation processes, such as the membrane damage at metabolic and structural levels, the leakage of intracellular components, the entrance of extracellular reactive oxygen species (ROS) to cytoplasm, and the decomposition of genomic DNA, are thoroughly investigated. The characterization and theoretical calculation results corroborate the interfacial interaction between the three moieties in the heterojunction, and thus efficient charge transfer occurs, thereby enhancing the photocatalytic ROS generation amount for efficient water disinfection. The bacterial inactivation mechanism is investigated in a scavenger study, •O2− and H2O2 are identified as the major ROS for bacterial inactivation. In addition, the MCNTs/RP/CN shows applicability in the authentic water matrices, toward a variety of pathogenic microorganisms (Gram-positive and Gram-negative bacteria, antibiotic-resistant bacteria, and oocysts of C. parvum), and in the large-scale demonstration application. The results of this work suggest that MCNTs/RP/CN can serve as a high-performance and recyclable photocatalyst for real-world photocatalytic disinfection operations.

Schottky barrier height mediated Ti3C2 MXene based heterostructure for rapid photocatalytic water disinfection: Antibacterial efficiency and reaction mechanism

Schottky barrier plays a key role in determining the interface electron transfer of most Schottky junctions, but the relationship between schottky barrier height (SBH) and photocatalytic disinfection activity is not clearly revealed. Here, a well-designed tubular graphitic carbon nitride/hydroxyl terminated Ti3C2 MXene (TCN/TC(OH)) Schottky junction with controllable SBH was prepared as a model case for investigation. Experimental study and density functional theory calculation confirm that the surface hydroxyl termination of Ti3C2 can lower the SBH of TCN/TC(OH) by reducing its work function (0.23 eV). The lowered SBH ensures rapid interface transfer of photogenerated electron, which decreases the average surface recombination rate from 0.0077 s−1 (TCN/TC) to 0.0045 s−1 (TCN/TC(OH)-3) and increases the corresponding surface charge transfer efficiency from 48.2% to 53.2%. Rotating disk electrode measurement confirms that different from the two-step single-electron O2 reduction of TCN/TC (n = 1.54), TCN/TC(OH)-3 (n = 1.95) exhibits a one-step two-electron reduction route, which is more selective for the generation of the major antibacterial reactive oxygen species H2O2. Consequently, TCN/TC(OH)-3 presents much higher photocatalytic performance towards natural water disinfection, and can entirely inactivate 7 × 107 CFU/mL of Staphylococcus aureus even in complex water matrix (interfering ions, acidic solution and real water samples). Our work provides a feasible guidance for future natural water purification by interfacial engineering of the MXene-based Schottky junction.

Regulating crystallinity in linear conjugated polymer to boost the internal electric field for remarkable visible-light-driven disinfection

• A new poly-imines, ODA-BPAH was used for photocatalysis disinfection • The high crystallinity greatly enhanced Internal electric field (IEF) • Giant IEF boosting photogenerated charge separation and transport • The ODA-BAPH exhibited excellent broad-spectrum water disinfection performance • This sterilization ability is higher than reported noble metal-free photocatalysts Conjugated linear polymers are promising metal-free photocatalysts for visible-light-driven photocatalytic water disinfection, but it was still bottlenecked by the insufficient photogenerated charge separation and transport (CST) process. Herein, we obtained the highly crystalline imine-linked conjugated linear polymer (ODA-BPAH) with a greatly enhanced CST process. The highly crystalline ODA-BPAH exhibited excellent broad-spectrum water disinfection efficiency up to 99.99999% in 1 h, which is among the reported highest of state-of-the-art photocatalysts. The crystallinity of ODA-BPAH was regulated by simply turning the solvent and the experiment results revealed that the ODA-BPAH with high crystallinity exhibited higher internal electric field strength and photocatalytic performance than that with low crystallinity, which indicates that higher crystallinity in linear conjugated polymers contributes to superior CST efficiency as well as the generation of reactive oxygen species. This work highlights the impact of polymer crystallinity on the internal electric field and proves that linear poly-imine could be a new type of promising metal-free photocatalyst for water treatment.

A Systematic Review on Solar Heterogeneous Photocatalytic Water Disinfection: Advances over Time, Operation Trends, and Prospects

Access to drinking water is a human right recognized by the United Nations. It is estimated that more than 2.1 billion people lack access to drinking water with an adequate microbiological quality, which is associated to 80% of all diseases, as well as with millions of deaths caused by infections, especially in children. Water disinfection technologies need a continuous improvement approach to meet the growing demand caused by population growth and climate change. Heterogeneous photocatalysis with semiconductors, which is an advanced oxidation process, has been proposed as a sustainable technology for water disinfection, as it does not need addition of any chemical substance and it can make use of solar light. Nevertheless, the technology has not been deployed industrially and commercially yet, mainly because of the lack of efficient reactor designs to treat large volumes of water, as most research focus on lab-scale experimentation. Additionally, very few applications are often tested employing actual sunlight. The present work provide a perspective on the operation trends and advances of solar heterogeneous photocatalytic reactors for water disinfection by systematically analyzing pertaining literature that made actual use of sunlight, with only 60 reports found out of the initially 1044 papers detected. These reports were discussed in terms of reactor employed, photocatalyst used, microorganism type, overall disinfection efficiency, and location. General prospects for the progression of the technology are provided as well.

Atomic Ti-Nx sites with switchable coordination number for enhanced visible-light photocatalytic water disinfection

Photocatalytic sterilization represents one of the promising strategies for efficient utilization of solar energy to remove hazardous materials, mainly based on the development of intrinsic materials with intact structures that actually cannot be absolutely remained under light irradiation but ignored in most cases. Herein, novel single titanium atoms anchored on g-C3N4 photocatalysts were facilely prepared by calcination of g-C3N4 with bis(cyclopentadienyl)dicarbonyl titanium. The introduction of single Ti atoms in g-C3N4 promoted photocatalytic efficiency by improving the separation efficiency of carriers with a broad visible-light-responsive range and reducing the energy barrier for the transfer of superoxide radicals to hydroxyl radicals. Especially, upon light-driven interaction with adsorbed O2, the photocatalyst coordination number could be remarkably regulated in situ from Ti–N6 to Ti–N4, which led to a more efficient generation of clean active substances in disinfectants (O2•− and •OH). As a result, the single Ti catalyst showed superior activity in the photocatalytic disinfection of bacteria and excellent recyclability. The inactivation of E. coli for the CN–Ti50 sample was 91.2% under irradiation for 30 min, which was 9.9 times that of pure g-C3N4. This in situ activation approach opens a new avenue for engineering efficient and energy-saving catalysts for water sterilization.

Efficient and reusable photocatalytic river water disinfection by addictive graphitic carbon nitride/magnesium oxide nano-onions with particular “nano-magnifying glass effect”

Photocatalytic disinfection is a promising way to combat bacterial pollution in the water environment. Inefficient use of visible light and undirected diffusion of reactive oxygen species (ROS) reduce photocatalytic disinfection efficiency. Herein, inspired by the concentrating effect of convex lens, photocatalysts with particular “nano-magnifying glass effect” (TCNMgNOs) were designed by embedding magnesium oxide with “converge effect” into the tailored hierarchical triple-shell porous g-C3N4 with “one light multi-purpose effect” to boost the visible-light utilization. Meanwhile, the ATPase hydrolysis homeostasis of bacteria was destroyed by TCNMgNOs to achieve the targeted movement of ROS. The results confirmed that the photocatalytic sterilization efficiency of TCNMgNOs was amplified by 30 times over g-C3N4, which was achieved by focusing visible light, multiple reflecting visible light and light transmission within the porous thin shells as well as the “addictive sterilization mechanism”. The sterilization efficiency still maintains 98.8 % (15 min) after 6 rounds recycling and reusing in practical river water disinfection. A novel pathway for fighting against microbial contaminants in natural water was explored.

Superior UVA-photocatalytic antibacterial activity of a double-layer ZnO/Al2O3 thin film grown on cellulose by atomic layer deposition (ALD)

Cellulose fibers coated with a double-layer ZnO/Al2O3 thin film (cel/Al2O3/ZnO) were prepared in-situ by two successive processes of atomic layer deposition (ALD). Photoinactivation kinetics of Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria were investigated in the dark and under UVA irradiation. Compared to the initial cellulose sample (cel) and cellulose coated with an Al2O3 thin film (cel/Al2O3), superior UVA photoinhibition was achieved for both bacteria treated with cel/Al2O3/ZnO within only 30 and 45 min of UVA irradiation for E. coli and S. aureus, respectively. FE-SEM and STEM micrographs showed strongly destructive effects on the morphology of both bacterial cell walls and the cytoplasmic membrane, which were attributed to the photogenerated reactive oxygen species (ROS). The kinetic data were successfully fitted using the modified Hom model, which consists of three rate constants describing the initial shoulder, rapid log-linear, and tail regions of the curves. As our results show, this cellulose-based material, further stabilized by the ALD Al2O3 interlayer, is promising for efficient photocatalytic disinfection of water.

Construction of carbon nanotubes bridged MoS2/ZnO Z-scheme nanohybrid towards enhanced visible light driven photocatalytic water disinfection and antibacterial activity

We fabricated carbon nanotubes (CNTs) bridged MoS2/ZnO nanohybrids from the hydrothermal process for the heterostructure photocatalysts. The nanohybrids were effectively operated as visible light action for the photocatalytic of organic compounds and heavy metal reduction. The results exhibit that the great photocatalytic efficiency from nanohybrids for the 94.5% of tetracycline (TC) degradation after 60 min of irradiation. Enhanced environmental pollutants removal was due to inhibition in recombination of photogenerated electron-hole pairs. The nanohybrids also displayed better photocatalytic performance and reduction capacity (Cr (VI) ions removal), about 10–15 folds as greater than that of bulk MoS2, and ZnO photocatalysts. The nanohybrid showing a wonderful photocatalytic antibacterial capability of 99.9% towards E. coli after 5 min and supplying a favourable environmentally friendly for water disinfection. Based on this studies, we believe that a promising candidate nanohybrids for the photocatalytic of various water contaminants under visible light activity.

The Benefits of Using Saccharose for Photocatalytic Water Disinfection.

In this work, the characteristics of saccharose (sucrose)-modified TiO2 (C/TiO2) photocatalysts obtained using a hydrothermal method at low temperature (100 °C) are presented. The influence of C/TiO2 on survivability and enzyme activity (catalase and superoxide dismutase) of Gram-negative bacteria Escherichia coli (ATCC 29425) and Gram-positive bacteria Staphylococcus epidermidis (ATCC 49461) under UV-A and artificial solar light (ASL) were examined. The obtained TiO2-1%-S-100 photocatalysts were capable of total E. coli and S. epidermidis inactivation under ASL irradiation in less than 1 h. In addition, the impacts of sugars on the photocatalytic activity and disinfection performance are discussed.

A Review of the Use of Semiconductors as Catalysts in the Photocatalytic Inactivation of Microorganisms

Obtaining clean and high-quality water free of pathogenic microorganisms is a worldwide challenge. Various techniques have been investigated for achieving an effective removal or inactivation of these pathogenic microorganisms. One of those promising techniques is photocatalysis. In recent years, photocatalytic processes used semiconductors as photocatalysts. They were widely studied as a green and safe technology for water disinfection due to their high efficiency, being non-toxic and inexpensive, and their ability to disinfect a wide range of microorganisms under UV or visible light. In this review, we summarized the inactivation mechanisms of different waterborne pathogenic microorganisms by semiconductor photocatalysts. However, the photocatalytic efficiency of semiconductors photocatalysts, especially titanium dioxide, under visible light is limited and hence needs further improvements. Several strategies have been studied to improve their efficiencies which are briefly discussed in this review. With the developing of nanotechnology, doping with nanomaterials can increase and promote the semiconductor’s photocatalytic efficiency, which can enhance the deactivation or damage of a large number of waterborne pathogenic microorganisms. Here, we present an overview of antimicrobial effects for a wide range of nano-photocatalysts, including titanium dioxide-based, other metal-containing, and metal-free photocatalysts. Promising future directions and challenges for materials research in photocatalytic water disinfection are also concluded in this review.

Enhanced singlet oxygen generation in PCN-224-Zn without the need of electron-hole separation for efficient photocatalytic water disinfection

Photocatlytic water disinfection for pathengenic miroorgasnisms removal is of great importance to public health safety, however the photocataltyic performance is unsatisfactory due to the low reactive oxygen species (ROS) generation. In this work, an innovative energy-transfer-mediated oxygen activation system on PCN-224-Zn is proposed for selective singlet oxygen generation without the need of electron-hole separation. The as-prepared PCN-224-Zn exhibits remarkable singlet triggered photocatalytic E-coli inactivation and organic pollutant degradation performance. The enhanced photocatalytic activity is attributed to the introduction of Zn into the metal-organic frameworks (MOFs) that facilitates the transformation of electron-hole couple from singlet to triplet state for selective singlet oxygen generation with high efficiency. This work provides a new oxygen activation pathway for efficient and selective ROS generation without the need of electron-hole separation.

Nanowire-Assisted Photocatalytic Water Disinfection

The water demand is projected to grow by 20% to 30% by the year 2050 as compared to 2018 to sustain the 2050 projected population of 9.4 to 10.2 billion [1]. As the demand for treated water useful for domestic, agricultural and industrial purposes increases, the current water supply and treatment infrastructure will be strained and will prove to be insufficient to meet this increased demand. The removal of emerging contaminants, such as pharmaceuticals, drug-resistant pathogens, and ‘forever chemicals’ make water treatment all the more challenging. Photocatalysis may serve as a great compliment to the existing train of treatment technologies in meeting this challenge. Photocatalysis could be employed to remove a wide variety of contaminants from water, ranging from organic and inorganic contaminants to pathogens, Moreover, if implemented in an effective manner, the photocatalysts employed to treat water could be recovered and reused. This, coupled with the use of renewable sources of energy, makes photocatalysis a sustainable process for water treatment on a large scale.While various materials have been investigated as photocatalysts for water remediation, Titanium dioxide (TiO2) is one of the most widely studied materials for this purpose. Various forms of TiO2, such as commercially available Aeroxide® P25, phase pure nanoparticles in Anatase as well as Rutile phases, and also alternative forms of TiO2 such as nanowires, have been explored for removal of dyes, pathogens etc. from water. Here, the capability of TiO2 in generating reactive oxygen species (ROS) when exposed to ultraviolet (UV) light is enhanced by the high specific surface areas of nanostructured TiO2. While the small size of the nanocrystalline photocatalyst is advantageous for enhancing kinetics, it may also be one of the major hurdles in the widespread use of photocatalysis for water treatment purposes. Enhanced scattering of light by nanostructured photocatalyst may make the process inefficient in certain cases. Also, the recovery and reuse of the nanostructured catalyst may be tedious.In this context, developing a roadmap towards scaling up the photocatalysis process, initially to a pilot plant scale and eventually to commercial scale is important for real-world applications of photocatalysis for water remediation. In this presentation, we will present a few strategies useful for accomplishing this goal. Changes to the catalyst morphology and their chemical composition, and the reactor geometry that have been implemented to make the photocatalysis process useful for treating large quantities of water, along with strategies developed for easy recovery and reuse of the photocatalyst will be discussed in detail in this talk.REFERENCES Boretti, A., Rosa, L. Reassessing the projections of the World Water Development Report. npj Clean Water 2, 15 (2019). https://doi.org/10.1038/s41545-019-0039-9