Photocatalytic Sterilization Research Articles

Metal free benzothiadiazole-diketopyrrolopyrrole-based conjugated polymer/g-C3N4 photocatalyst for enhanced sterilization and degradation in visible to near-infrared region

In recent years, photocatalytic technology has attracted wide attention in environmental treatment, exploring non-toxic and metal-free photocatalysts is imminent to meet sustainable development. However, semiconductors with wide spectral response are rarely studied and applied in the field of photocatalysis. Herein, a new narrow band-gap polymer PFBDT-DPP (P3) with wide absorption from 500 to 860 nm was synthesized and further constructed heterostructure with g-C3N4 for photocatalytic sterilization and degradation of organic pollutant Rhodamine B (RhB). The optimal antibacterial rate for Escherichia coli reached 99.8% after 190 min of light irradiation and for Staphylococcus aureus reached 96.8% after 120 min of irradiation, and the highest degradation efficiency of RhB by P3/g-C3N4 was 98.9% within 60 min light irradiation, while g-C3N4 displayed an unsatisfactory sterilization and photodegradation performance. This is mainly attributed to the broadened light absorption range and enhanced carrier separation efficiency of P3/g-C3N4. This work could provide a new strategy to fabricate metal-free photocatalysts with high utilization of sunlight and excellent photocatalytic performance.

Synthesis of MXene/COF/Cu2O heterojunction for photocatalytic bactericidal activity and mechanism evaluation

Reasonably combining the advantages of heterojunction constructed by a variety of two-dimensional materials and metal oxide nanoparticles (NPs) is an effective strategy to improve the efficiency of photocatalytic sterilization. In this work, TpPa-1-COF, as a stable semiconductor, was in situ grown on Ti3C2-MXene through the Schiff base reaction and anchored with Cu2O NPs to obtain an efficient photocatalytic bactericide. Electrochemical impedance spectroscopy and photoluminescence spectra of nanocomposites showed that the photogenerated carrier migration rate as well as the production of reactive oxygen species was improved and the carrier life was prolonged. The work function at the interface was analyzed by using the first principle calculation based on density functional theory. Both TpPa-1/Ti3C2 interface and Ti3C2/Cu2O interface had large built-in electric field to promote the migration of carriers between layers, so as to realize efficient photocatalysis and reduce photo-corrosion. The obtained Ti3C2/TpPa-1/ Cu2O nanocomposites showed excellent antibacterial rates against S. aureus and P. aeruginosa, which were antibacterial rates of 98.90% and 99.62% and were increased by 50% and 33% compared with pure TpPa-1-COF. It provides a new idea for the development of photocatalytic bactericides in the field of marine antifouling.

Building P-doped MoS2/g-C3N4 layered heterojunction with a dual-internal electric field for efficient photocatalytic sterilization

The construction of internal electric field (IEF) is usually considered an effective strategy to enhance photocatalytic efficiency because of its significant role in photo-induced carrier separation. Herein, we report a novel method to synthesize phosphorus-doped (P-doped) MoS2/g-C3N4 layer-by-layer composite, which could expose more active sites and generate a strong interaction by forming Mo-N bonds for photocatalytic sterilization. It is experimentally and theoretically confirmed that P-doped MoS2/g-C3N4 heterojunctions not only generate a dual-IEF to drive charge migration, but also facilitate spatially separated redox sites to further promote the separation of photo-induced carrier. The optimized P-doped MoS2/g-C3N4 layered heterojunction exhibits high photocatalytic sterilization efficiency (99.99%) towards E. coli under visible-light irradiation, which is remarkably higher compared with those of P-doped g-C3N4 (44.73%) and P-doped MoS2 (61.69%), respectively. This research will offer a novel method of designing and synthesizing layered composite photocatalyst with a dual-IEF for effective photocatalytic sterilization.

Performance tuning and optimisation of 2D–2D-like g-C3N4 modified Bi2O2CO3 n–n homotypic heterojunction as an inactivating photocatalytic material

Semiconductor photocatalysts applied to inactivate marine microorganisms，It has been proved to be an environmentally efficient means of improving the Marine environment. To overcome the problem of limiting light response range causing by the wide bandgap of Bi2O2CO3 photocatalyst, the photocatalytic activity of Bi2O2CO3 was improved by surface modification with the introduction of g-C3N4. In this paper, g-C3N4/BOC heterojunctions were prepared by a convenient general hydrothermal method combining with assisted ultrasonication. The photocatalytic sterilisation activity was also verified under simulated sunlight irradiation. By X-ray diffraction (XRD)、X-ray photoelectron spectroscopy (XPS)、scanning electron microscopy (SEM) and transmission electron microscopy (TEM), it was ensured that the system contains g-C3N4, and g-C3N4 is attached to the outer layer of Bi2O2CO3 flower ball-like microspheres in an irregular nanosheet-like morphology. The 2D–2D heterojunction morphology is formed. By UV-Vis diffuse reflectance spectroscopy (DRS), electrochemical characterization, and photoluminescence spectroscopy (PL). I verified the formation of n-n homotype heterojunction between g-C3N4 and Bi2O2CO3. Compared with Bi2O2CO3 catalyst, the light-induced photogenerated electron-hole pairs of g-C3N4/BOC photocatalyst are separated efficiently. In addition, after 5 cycles of stability tests, the g-C3N4/BOC composite photocatalyst was verified to have good environmental catalytic stability. The 10CNB composite photocatalyst proclaimed the highest photocatalytic sterilization activity, reaching 95%. The catalytic performance is 5 times higher than that of pure BOC photocatalyst and 3.4 times higher than that of pure g-C3N4 photocatalyst. By testing the active substance, the hydroxyl radical (•OH) is a significant contribution to the photocatalytic sterilisation process.

H2O2-assisted photocatalysis induced by SPR of BiQDs anchored on BiVO4 for the production of hydroxyl radicals in seawater

Ballast water is an essential component of nautical navigation, however, the microorganisms present in the water may be an environmental hazard. Therefore, the decontamination of ballast water has been widely studied. The anchoring of metal nanoparticles with plasmonic properties into semiconductors is an effective way to enhance their photocatalytic activity for the inactivation of marine microorganisms in ballast water. In this paper, we describe the successful synthesis of BiQDs/BiVO4 via a facile solvothermal method and evaluated their capacity to inactivate marine microorganisms under visible light irradiation. The results showed that 3%BiQDs/BiVO4 exhibited greatest photocatalytic sterilization efficiency with the low concentration of H2O2 present in real seawater. Further results revealed that the BiQDs had a diameter of approximately 5.1 nm and were distributed randomly on BiVO4, and that the SPR effect of BiQDs enhanced the utilization of visible light. The hydroxyl radical was proven to be the main active species and the addition of H2O2 promoted the generation of ·OH to achieve the efficient decontamination of ballast water. This study may provide a potential route for the photocatalytic removal of marine microorganisms and ballast water tank protection.

Plasmonic Ag supported on Ni-doped TiO2 nanospheres for rapid microbial inactivation under visible light

Ni-doped TiO2 nanospheres decorated with silver plasmonic nanoparticles (Ni-TiO2/Ag) have been successfully synthesized via sol-gel method and photo-deposition approach. In contrast with pure TiO2 and Ni-TiO2, the Ni-TiO2/Ag composite photocatalysts exhibit markedly enhanced visible-light photocatalytic sterilization efficiencies towards Escherichia coli (E. coli). And more importantly, antifungal experiment reveals that the composite can also disinfect ca. 2.0 log10 cfu·mL−1Fusarium graminearum (F. graminearum) macroconidia within 3 h. The highly efficient antimicrobial activities are ascribed to the introduction of Ni doping and Ag nanoparticles, which increases the visible light utilization and promotes the separation of electron-hole pairs. The photocatalytic disinfection mechanism is studied with scavengers trapping experiments and electron spin-resonance spectroscopy (ESR), which verifies the key role of •O2- and •OH during the microbial inactivation. Our study indicates that the Ni-TiO2/Ag nanocomposite has great potential for use in pathogenic microorganism remediation.

The facile fabrication and structural control of carbon‐MIL‐125 by coupling pre‐hydrolysate and Ti‐MOF for photocatalytic sterilization under visible light

AbstractBACKGROUNDCarbon‐MIL‐125 can be successfully prepared from pre‐hydrolysate and metal oxide TiO2 (Ti‐MOF) by coupling hydrothermal and carbonization processes. The use of this pre‐hydrolysate to prepare carbon (C)‐based materials could provide a value‐added product and allow the more complete use of bioresources. Combining the photocatalytic bactericidal properties of Ti‐MOF and adsorption capacity of biomass‐based C materials could further improve the antibacterial efficiency of the materials, and C could expand the response range of TiO2 to light and reduce the reorganization rate of photogenerated electrons and holes. This strategy could potentially increase the rate and efficiency of catalytic reactions.RESULTSThe morphologies and structures of samples were controlled via one‐ and two‐step routes. The obtained samples exhibited 1‐2 μm size and different morphologies. C1‐MIL‐125 showed a spherical morophology via ont‐step, C2‐MIL‐125 displayed a new type of rough tablet structure via two‐step. Meanwhile, Ti exists in the form of the mixture of TiO2 in the anatase and rutile phases. The catalytic activity of mixed TiO2 forms is higher than pure anatase or rutile, removal of Escherichia coli could reach 99.00% and 98.67% under a xenon lamp via one‐ and two‐step processes, respectively.CONCLUSIONThis work could realize high value‐added utilization of biomass and is expected to provide new prospects for the design of superior photocatalysts for water disinfection. © 2021 Society of Chemical Industry

Metal-free polymeric carbon nitride photocatalytic bactericide: precursor-controlled killing activity of E. coli

The photocatalytic sterilization activity of polymeric carbon nitride is closely related to its microstructure. In this study, four kinds of polymeric carbon nitride were prepared with melamine, dicyandiamine, thiourea and urea as precursors respectively. These polymeric carbon nitrides were similar in crystallinity and bonding, but differ significantly in texture, optical and photoelectrochemical properties. These changes resulted in different performances of polymeric carbon nitrides in their photocatalytic activities to kill E. coli. The polymeric carbon nitride prepared from urea exhibited significantly better photocatalytic antibacterial activity than other control samples. The advantage of the activity should be attributed to the synergy of many favorable factors, such as the shape of flake, large specific surface area, open pore structure, high valence band potential, low photogenerated carrier recombination rate, large photocurrent density and low electron transfer impedance. This study showed that urea-derived polymeric carbon nitride is very promising for the preparation advanced materials with higher photocatalytic sterilization activity.

Morphology modulation and performance optimization of nanopetal-based Ag-modified Bi2O2CO3 as an inactivating photocatalytic material

The use of photocatalytic technology to kill bacteria on marine vessel surface coatings has been paid more attention by research scholars. In this paper, petal-like microspheres with Ag nanoparticles were prepared by a simple one-step process combining the hydrothermal method and photodeposition. The 0.7% Ag/Bi2O2CO3 composite photocatalyst exhibited the highest photocatalytic efficiency for bacterial removal under visible light irradiation and had the highest photogenerated carrier separation efficiency, and the sterilization rate was doubled compared with that of pure Bi2O2CO3, reaching 95%. Using X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy, the existence of Ag nanoparticles was confirmed, and their size was approximately 10 nm. The surface plasmon resonance (SPR) effect of Ag nanoparticles was investigated by ultraviolet–visible diffuse reflectance spectroscopy (DRS). It was shown that the surface plasmon resonance effect of Ag improved the spectral utilization of the Ag/Bi2O2CO3 composite photocatalyst and enhanced the stability of the catalyst. This caused the Ag/Bi2O2CO3 composite photocatalyst to have superior photocatalytic activity to pure Bi2O2CO3. The results of electrochemical impedance characterization and transient photocurrent response show that 0.7% Ag/Bi2O2CO3 has a high efficiency of photogenerated carrier separation. By the free radical capture test, hydroxyl radicals were the primary active substance, and Ag+ improved the photocatalytic sterilization activity.

Constructing built-in electric field in graphitic carbon nitride hollow nanospheres by co-doping and modified in-situ Ni2P for broad spectrum photocatalytic activity

The construction of built-in electric field is generally considered as an effective strategy to enhance photocatalytic performance due to its significant role in charge separation. Herein, a built-in electric field within g-C3N4 hollow nanospheres co-doped with sulfur and oxygen and modified in-situ Ni2P is proposed. Ni2P/SOHC3N4 exhibits significantly enhanced board spectrum photocatalytic properties for hydrogen precipitation (5.21 mmol h−1 g−1) and photocatalytic Cr(VI) reduction without the use of noble metal. It also achieves high photocatalytic sterilization activity and remarkable stability when used to completely inactivate E. coli (107) in 60 min under Vis-NIR light irradiation. The enhanced performance is attributed to the formation of a curved hollow sphere structure, which promotes the electron transfer between the inner and outer layers. In addition, co-doping inhibits the recombination of photogenerated carriers, and the built-in electric field recombined with Ni2P facilitates the electron transfer between the composite interfaces. This design strategy demonstrates an original method of devising multifunctional photocatalysts with enhanced activity and stability.

Different antibacterial effect of Ag3PO4/TiO2 heterojunctions and the TiO2 polymorphs

Herein, we analyzed the antibacterial effect of the TiO2 polymorphs and Ag3PO4/TiO2 heterojunctions. The sol-gel-derived TiO2 was calcined at 400 °C, 550 °C and 700 °C to get different polymorphs. Subsequently, Ag3PO4/TiO2 composites were synthesized by the in-situ precipitation method. These photocatalysts were characterized by XRD, TEM, UV–VIS–NIR, XPS, FP, AAS, and SEM. Photocatalytic sterilization was employed by the transferring and spreading tests with Gram-positive S. aureus (ATCC 25933) and Gram-negative E. coli (ATCC 25922) bacteria. It was noted that the anatase TiO2 has better antibacterial effect than rutile. And there was an existing synergetic effect between these two polymorphs. Besides partially preventing the photo corrosion, the Ag3PO4/TiO2 heterojunctions exhibit a remarkable bactericidal activity and almost completely collapse the high concentration bacterial cells. Moreover, The Ag3PO4/TiO2 heterojunctions show more pronounced in E. coli than S. aureus for their different cellular structure. The sterilization of the tolerant Gram-positive bacteria often needs the assistance of Ag-ion, while Gram-negative E. coli is more sensitive to •O2− radicals, and h+ during the photocatalytic sterilization.

Analyses of the Effect of Peptidoglycan on Photocatalytic Bactericidal Activity Using Different Growth Phases Cells of Gram-Positive Bacterium and Spheroplast Cells of Gram-Negative Bacterium

We conducted photocatalytic experiments focusing on the peptidoglycan layer to elucidate the details of the mechanism of photocatalytic sterilization. The previous study of our laboratory suggested that the presence of the peptidoglycan layer increases the bactericidal effect. To further verify it, the following experiments were performed: experiments on cells with different peptidoglycan layer thickness used Lactobacillus plantarum cells with different growth phases, experiments on cells with the thin peptidoglycan layer used Escherichia coli cells and spheroplast cells from which the peptidoglycan layer was removed from E. coli cells. The bactericidal effects increased as the growth progresses of L. plantarum. It was confirmed by TEM that the thickness of the peptidoglycan layer increased with cell growth. The survival rates of E. coli intact cells were significantly lower than those of spheroplast cells. These results strongly suggest that the peptidoglycan layer enhances the photocatalytic bactericidal effect. As a result of allowing the photocatalytic reaction to act on peptidoglycan, the amount of hydroxyl radical was smaller, and the amount of hydrogen peroxide was higher than in the absence of peptidoglycan. It is suggested that peptidoglycan may convert produced hydroxyl radical to hydrogen peroxide.

Lactose-containing glycopolymer grafted onto magnetic titanium dioxide nanomaterials for targeted capture and photocatalytic killing of pathogenic bacteria

The superior photocatalysis of titanium dioxide (TiO2) had received much attention, but the effect of its separation and agglomeration on the water disinfection performance should not be ignored. Herein, lactose-containing glycopolymers grafted onto magnetic TiO2 nanomaterials were prepared through copper (0) mediated controlled radical polymerization and “grafting to” strategy to improve their separation and dispersibility properties. The physicochemical properties of the Fe3O4@TiO2/glycopolymers were systematically characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, dynamic light scattering, transition electron microscopy, and vibrating sample magnetometer. The result of the survival bacterial ratio under ultraviolet exhibited the well photocatalytic antibacterial activity of Fe3O4@TiO2/glycopolymers towards E. coli, which retained the photocatalytic sterilization performance of TiO2. Among them, Fe3O4@TiO2@poly(LacA) showed an excellent ability to identify and trap E. coli because of the carbohydrate-protein recognition effect. The endocytosis of E. coli on Fe3O4@TiO2@poly(LacA) was further confirmed by the image of transition electron microscopy. Considering the magnetic characteristics of Fe3O4@TiO2/glycopolymers, it is speculated that these antibacterial agents can be easily recovered by the external magnetic field, and thus be a promising candidate for photocatalysis water disinfection.

Design of Ti3C2ZnOAlN ternary nanocomposite for photocatalytic antifouling: a first-principle study

Photocatalytic antifouling has been proved to be an efficient method to restrain marine biofouling. In this work, a new photocatalyst with superior photocatalytic performance was designed based on first-principle calculation. Two-dimensional (2D) zinc oxide (ZnO) and aluminum nitride (AlN) based on (001) crystal plane were selected to construct the new catalyst, which could effectively adjust their band gap and band edge alignment. However, the stress and strain under lattice distortion would damage their direct band gap characteristics, even affecting their stability. To eliminate these effects, titanium carbide (Ti3C2) MXenes was used as substrate to carry 2D-ZnO and 2D-AlN (Ti3C2ZnOAlN), in which Ti3C2 played as a co-catalyst. The results reveal that the designed composite structure has a low work function and is a type II heterostructure, which can achieve the separation of photo-generated electrons and holes efficiently. The phonon frequency comparison results indicate that participation of Ti3C2 greatly improves the dynamic stability of the structure. An asymmetric built-in electric field at the interface further reduces the work function and is considered to be the main reason for the rapid migration of carriers in the direction of the interface. At the same time, the light absorption peaks in the Ti3C2ZnOAlN composite structure are red-shifted and produce a high coincidence with the main irradiation intensity of solar flux. The triple interfaces are also helpful to improve the utilization of incident photons in all directions. According to the results of the band edge position and Nernst equation, it can be concluded that the Ti3C2ZnOAlN composite material can meet the ROS reaction conditions under any pH environments, so it should be an environmentally adaptable photocatalytic sterilization material for antifouling.

Structural characterization and catalytic sterilization performance of a TiO2 nano-photocatalyst.

In view of the food safety and hygiene issues caused by pathogenic microorganisms, tetrabutyl titanate was used as a precursor for the preparation of a TiO2 nano‐semiconductor photocatalyst via the sol–gel process. The plate count method was then adopted to investigate the photocatalytic sterilization performance of the synthesized TiO2 nanoparticles toward Escherichia coli, Staphylococcus aureus, and Candida albicans. Subsequently, a backpropagation (BP) neural network model was developed to predict the photocatalytic sterilization performance. The photocatalyst was structurally characterized by the Brunauer–Emmett–Teller method for specific surface area determination, transmission electron microscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy. The results indicated that the prepared TiO2 nano‐photocatalyst was of high purity with a specific surface area of 76.5 m2/g and the particle size range 15–18 nm. The nanoparticles exhibited characteristic peaks corresponding to the oxide component Ti–O, hydroxyl group ˙OH and oxygen chemisorbed and presented an anatase‐dominated multiphase structure that enhanced the photocatalytic performance. UV irradiation at 254 nm produced better sterilization effects on E. coli, S. aureus, and C. albicans, with elimination rates after 30 min of reaction of 97.8%, 99.4%, and 93.6%, respectively. These results indicated that the TiO2 nano‐photocatalyst is a promising environmentally friendly catalyst with good sterilization performance. The constructed BP neural network also exhibited high training accuracy and good generalization ability, with correlation coefficients between the network‐predicted and experimental target values of 0.9789. These results support research on the intelligent processing of photocatalytic sterilization with TiO2 nanoparticles.

Synthesis and Photocatalytic Sterilization Performance of SA/TiO2.

The photocatalyst sorbic acid (SA)/titanium dioxide (TiO2) was successfully synthesized by sol–gel method and characterized. The composite exhibited regularly spherical particles with the size of 50 nm and the specific surface area of 90.3 m2 g−1, furthermore, it showed mesoporous structure and significantly improved dispersion. SA was grafted on TiO2 surface by –COOTi and TiO2 existed as pure anatase phase in the composite. The addition of SA made the band gap of TiO2 increased from 3.03 to 3.35 eV, which indicting that the composite exhibited a strong response to the ultraviolet light. The optimum preparation parameters of the catalyst were as follows: n(Ti):n(SA) = 1:0.05, ethanol 60 mL, glacial acetic acid 40 mL, hydrothermal temperature 180 °C, hydrothermal time 12 h. The composite could reach the 4.31 log reduction of E. coli, with the optimum catalyst dosage of 0.7 g L−1, irradiated by UV light for 60 min. SA/TiO2 was an environmentally friendly, non-toxic and safe sterilized nanocomposite material appropriate for future bactericidal applications, providing a new way to effectively increase the dispersion of TiO2 particles to achieve superior photocatalytic sterilization efficiency.

Sterilization of Escherichia coli by Photothermal Synergy of WO3-x/C Nanosheet under Infrared Light Irradiation.

The application of photocatalytic sterilization technology for the sterilization of water has been broadly studied in recent years. However, developing photocatalysts with high disinfection efficiency remains an urgent challenge. Tungsten trioxide with coexisting oxygen vacancies and carbon coating (WO3-x/C) has been successfully synthesized toward the photothermal inactivation of Escherichia coli. Oxygen vacancies and carbon coating bring WO3-x/C strong absorption in the infrared region and enhance the carrier separation efficiency. As a result, a higher sterilization rate is obtained compared to WO3. WO3-x/C can completely inactivate E. coli under infrared light within 40 min through photothermal synergy process. During the process of inactivating bacteria over WO3-x/C, E. coli is killed by the destruction of their cell membrane to decrease the activity of enzymes and release the cell contents, which can be ascribed to the efficient generation of reactive oxygen species (O2•- and •OH) and thermal effect. This work demonstrates a novel approach for engineering efficient and energy-saving catalysts for water sterilization.

Designing a 0D/2D S-Scheme Heterojunction over Polymeric Carbon Nitride for Visible-Light Photocatalytic Inactivation of Bacteria.

Constructing heterojunctions between two semiconductors with matched band structure is an effective strategy to acquire high-efficiency photocatalysts. The S-scheme heterojunction system has shown great potential in facilitating separation and transfer of photogenerated carriers, as well as acquiring strong photoredox ability. Herein, a 0D/2D S-Scheme heterojunction material involving CeO2 quantum dots and polymeric carbon nitride (CeO2 /PCN) is designed and constructed by in situ wet chemistry with subsequent heat treatment. This S-scheme heterojunction material shows high-efficiency photocatalytic sterilization rate (88.1 %) towards Staphylococcus aureus (S. aureus) under visible-light irradiation (λ≥420 nm), which is 2.7 and 8.2 times that of pure CeO2 (32.2 %) and PCN (10.7 %), respectively. Strong evidence of S-scheme charge transfer path is verified by theoretical calculations, in situ irradiated X-ray photoelectron spectroscopy, and electron paramagnetic resonance.

Designing a 0D/2D S‐Scheme Heterojunction over Polymeric Carbon Nitride for Visible‐Light Photocatalytic Inactivation of Bacteria

AbstractConstructing heterojunctions between two semiconductors with matched band structure is an effective strategy to acquire high‐efficiency photocatalysts. The S‐scheme heterojunction system has shown great potential in facilitating separation and transfer of photogenerated carriers, as well as acquiring strong photoredox ability. Herein, a 0D/2D S‐Scheme heterojunction material involving CeO2quantum dots and polymeric carbon nitride (CeO2/PCN) is designed and constructed by in situ wet chemistry with subsequent heat treatment. This S‐scheme heterojunction material shows high‐efficiency photocatalytic sterilization rate (88.1 %) towards Staphylococcus aureus (S. aureus) under visible‐light irradiation (λ≥420 nm), which is 2.7 and 8.2 times that of pure CeO2(32.2 %) and PCN (10.7 %), respectively. Strong evidence of S‐scheme charge transfer path is verified by theoretical calculations, in situ irradiated X‐ray photoelectron spectroscopy, and electron paramagnetic resonance.

Nanomesh‐Structured Graphitic Carbon Nitride Polymer for Effective Capture and Photocatalytic Elimination of Bacteria

AbstractIt is valuable to design a photocatalyst semiconductor architecture that enables the effective contact with bacteria, since only random and momentary contact exists in most of the present photocatalytic antibacterial systems. Herein, nanomesh‐structured graphitic carbon nitride (g‐C3N4) a visible‐light photocatalyst was successfully prepared using SiO2 microspheres as template. The optimal pore size in the g‐C3N4 nanomesh was determined at the average diameter of about 500 nm of SiO2 microspheres, which matches the size of E.coli K‐12. Excluding the effect of electrostatic contact, the efficient contact between catalyst and bacteria was achieved, leading to increased capture and reaction time for killing bacteria. The porous structure promoted the light absorption and realized more active edge. As a result, the photocatalytic antibacterial activity and the leakage of K+ ions was greatly enhanced via .OH radical as the main active species. This work provided a new approach to photocatalytic sterilization for practical applications.