Preparation and characterization of photoactive antimicrobial graphitic carbon nitride (g-C3N4) films

Graphitic Carbon Nitride Enters the Scene: A Promising Versatile Tool for Biomedical Applications

Graphitic carbon nitride (g-C3N4), since the pioneering work on visible-light photocatalytic water splitting in 2009, has emerged as a highly promising advanced material for environmental and energetic applications, including photocatalytic degradation of pollutants, photocatalytic hydrogen generation, and carbon dioxide reduction. Due to its distinctive two-dimensional structure, excellent chemical stability, and distinctive optical and electrical properties, g-C3N4 has garnered a considerable amount of interest in the field of biomedicine in recent years. This review focuses on the fundamental properties of g-C3N4, highlighting the synthesis and modification strategies associated with the interfacial structures of g-C3N4-based materials, including heterojunction, band gap engineering, doping, and nanocomposite hybridization. Furthermore, the biomedical applications of these materials in various domains, including biosensors, antimicrobial applications, and photocatalytic degradation of medical pollutants, are also described with the objective of spotlighting the unique advantages of g-C3N4. A summary of the challenges faced and future prospects for the advancement of g-C3N4-based materials is presented, and it is hoped that this review will inspire readers to seek further new applications for this material in biomedical and other fields.

Ultrathin TiS2@N,S-Doped Carbon Hybrid Nanosheets as Highly Efficient Photoresponsive Antibacterial Agents

Nanobactericides are employed as a promising class of nanomaterials for eradicating microbial infections, considering the rapid resistance risks of conventional antibiotics. Herein, we present a pioneering approach, reporting the synthesis of two-dimensional titanium disulfide nanosheets coated by nitrogen/sulfur-codoped carbon nanosheets (2D-TiS2@NSCLAA hybrid NSs) using a rapid l-ascorbic acid-assisted sulfurization of Ti3C2Tx-MXene to achieve efficient alternative bactericides. The as-developed materials were systematically characterized using a suite of different spectroscopy and microscopy techniques, in which the X-ray diffraction/Raman spectroscopy/X-ray photoelectron spectroscopy data confirm the existence of TiS2 and C, while the morphological investigation reveals single- to few-layered TiS2 NSs confined by N,S-doped C, suggesting the successful synthesis of the ultrathin hybrid NSs. From in vitro evaluation, the resultant product demonstrates impressive bactericidal potential against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria, achieving a substantial decrease in the bacterial viability under a 1.2 J dose of visible-light irradiation at the lowest concentration of 5 μg·mL-1 compared to Ti3C2Tx (15 μg·mL-1), TiS2-C (10 μg·mL-1), and standard antibiotic ciprofloxacin (15 μg·mL-1), respectively. The enhanced degradation efficiency is attributed to the ultrathin TiS2 NSs encapsulated within heteroatom N,S-doped C, facilitating effective photogenerated charge-carrier separation that generates multiple reactive oxygen species (ROS) and induced physical stress as well as piercing action due to its ultrathin structure, resulting in multimechanistic cytotoxicity and damage to bacterial cells. Furthermore, the obtained results from molecular docking studies conducted via computational simulation (in silico) of the as-synthesized materials against selected proteins (β-lactamasE. coli/DNA-GyrasE. coli) are well-consistent with the in vitro antibacterial results, providing strong and consistent validation. Thus, this sophisticated study presents a simple and effective synthesis technique for the structural engineering of metal sulfide-based hybrids as functionalized synthetic bactericides.

Amphoteric dissolution of two-dimensional polytriazine imide carbon nitrides in water

Crystalline two-dimensional carbon nitrides with polytriazine imide (PTI) structure are shown to act amphoterically, buffering both HCl and NaOH aqueous solutions, resulting in charged PTI layers that dissolve spontaneously in their aqueous media, particularly for the alkaline solutions. This provides a low energy, green route to their scalable solution processing. Protonation in acid is shown to occur at pyridinic nitrogens, stabilized by adjacent triazines, whereas deprotonation in base occurs primarily at basal plane NH bridges, although NH2 edge deprotonation is competitive. We conclude that mildly acidic or basic pHs are necessary to provide sufficient net charge on the nanosheets to promote dissolution, while avoiding high ion concentrations which screen the repulsion of like-charged PTI sheets in solution. This article is part of the theme issue 'Exploring the length scales, timescales and chemistry of challenging materials (Part 2)'.

Boosting environmental remediation: harnessing the efficiency of graphitic carbon nitride stabilized on red ocher surface for enhanced photocatalytic remove of Escherichia coli

In the present study, the antibacterial effect of graphitic carbon nitride coated on the red ocher was investigated by the photocatalytic process to remove Gram-negative Escherichia coli bacteria. The concentration effects (0.025, 0.05, and 0.1 g/mL) of disinfectant, contact time (30, 60, and 90 min), and the number of bacteria (102, 104, and 106 CFU/mL) were examined. In this research, in each experiment, 100 mL of the sample was taken, and the test work was performed. The red ocher required for this project was obtained from Hormoz Island, Hormozgan Province, Iran. Melamine was used for the synthesis and manufacture of graphitic carbon nitride. A general-purpose media was used for microbial culture using the pour and spread plate methods, as well as an LED lamp with a wavelength of 420 nm as a light source for the photocatalytic process. To obtain the important factors, the interaction of the factors and the optimal experimental design were used through the response surface methodology (RSM) based on the Box-Behnken design. According to research findings, this method is effective in eliminating E. coli. The results showed that the increase in the amount of disinfectant from 0.025 to 0.1 g/mL and also the increase of contact time from 30 to 90 min accelerated the removal rate of E. coli. The numerical value of R2 obtained for the removal of E. coli was 0.9728, indicating good agreement between experimental and predicted data. Therefore, its utilization in water disinfection seems necessary, both to ensure human health and environmental protection.

Metal-organic frameworks doped with metal ions for efficient sterilization: Enhanced photocatalytic activity and photothermal effect

Photocatalytic and photothermal disinfection is a promising strategy for addressing the challenges of environmental microbial contamination. In this work, we choose a metal-organic framework (MOF), ZIF-8, as an inexpensive and ideal model for metal ion doping, and manipulate the band structure, thermal vibration in molecules, charge distribution, and robustness of the metal-ligand coordination bond of the metal-ion-doped ZIFs for their use in photo-disinfection. The effects of their absorption edge, rate of the photo-induced temperature rise, transient photocurrent response, photo-generated reactive oxygen species (ROS) type, and crystal stability on the photo-disinfection performance are systematically studied by varying the metal ion type (Co²⁺, Ni²⁺, or Cu²⁺) and doping concentration (1-100%). The results show that the efficiency of light harvesting and photogenerated carrier separation is facilitated in all doped ZIFs. The photothermal conversion gradually improves with the increasing concentration of doped Co²⁺/Cu²⁺. Remarkably, the photo-generated ROS type changes from the original singlet oxygen (¹O₂) to multiple ROS (¹O₂ and •O₂^-) due to the introduction of Co(II) sites. Consequently, compared with pristine ZIF-8 and other doped ZIFs, Co²⁺-doped ZIF-8 with a 5% doping concentration shows the highest sterilization efficiency (6.6 log₁₀ CFU mL^-1) against Escherichia coli (E. coli) under simulated sunlight within one hour by virtue of the enhanced photothermal effect and the generation of multiple ROS. This work provides insights into the application of metal-ion-doped MOF photocatalysts to the disinfection of environments with pathogenic microorganisms.

Facile synthesis of broom stick like FeOCl/g-C3N5 nanocomposite as novel Z-scheme photocatalysts for rapid degradation of pollutants

A simple and cost-effective route has been utilized for the preparation of a novel lamellar structured FeOCl/g-C₃N₅ nanocomposite as Z-scheme photocatalyst. The preparation method was performed under the ambient temperature conditions without any hazardous chemicals. Various characterization techniques, namely XRD, FESEM, TEM, FT-IR, UV-Vis, DRS, and PL were carried out to analyse the nanocomposite for confirmation of FeOCl/g-C₃N₅ nanocomposite. To evaluate its and visible light degradation performances tetracycline (T-C) was used as target pollutant. Among the optimum loading for the g-C₃N₅ incorporated FeOCl binary nanocomposites, the g-C₃N₅/FeOCl exhibited a superlative degradation performance toward the T-C antibiotic pollutant. The results confirmed that 95% of T-C was degraded within 40 min under photodegradation mechanism. The improved photodegradation performance in degradation of T-C was mainly due to the reduction in electron-hole recombination, broadening in the light absorption by g-C₃N₅ incorporation, which leads to shortening the degradation time. Furthermore, the hydroxyl and superoxide radicals played a major role in the photodegradation process and the possible mechanism was elucidated and proposed. The present work implies a novel, sustainable, and efficient Z-scheme system that may deliver a convenient method for environment remediation.

Enhanced Photocatalytic and Photoluminescence Properties Resulting from Type-I Band Alignment in the Zn2GeO4/g-C3N4 Nanocomposites

Well-defined Zn2GeO4/g-C3N4 nanocomposites with a band alignment of type-I were prepared by the ultrasound-assisted solvent method, starting from g-C3N4 nanosheets and incorporating 0, 10, 20, and 40 wt% of Zn2GeO4. In this study, we have investigated in-depth the photoluminescence emission and photocatalytic activity of these nanocomposites. Our experimental results showed that an increased mass ratio of Zn2GeO4 to g-C3N4 can significantly improve their photoluminescence and photocatalytic responses. Additionally, we have noted that the broadband photoluminescence (PL) emission for these nanocomposites reveals three electronic transitions; the first two well-defined transitions (at ca. 450 nm and 488 nm) can be attributed to π*→ lone pair (LP) and π*→π transitions of g-C3N4, while the single shoulder at ca. 532 nm is due to the oxygen vacancy (Vo) as well as the hybridization of 4s and 4p orbital states in the Zn and Ge belonging to Zn2GeO4. These experimental findings are also supported by theoretical calculations performed under periodic conditions based on the density functional theory (DFT) fragment. The theoretical findings for these nanocomposites suggest a possible strain-induced increase in the Zn-O bond length, as well as a shortening of the Ge-O bond of both tetrahedral [ZnO4] and [GeO4] clusters, respectively. Thus, this disordered structure promotes local polarization and a charge gradient in the Zn2GeO4/g-C3N4 interface that enable an efficient separation and transfer of the photoexcited charges. Finally, theoretical results show a good correlation with our experimental data.

Progress on photocatalytic semiconductor hybrids for bacterial inactivation

Due to its use of green and renewable energy and negligible bacterial resistance, photocatalytic bacterial inactivation is to be considered a promising sterilization process. Herein, we explore the relevant mechanisms of the photoinduced process on the active sites of semiconductors with an emphasis on the active sites of semiconductors, the photoexcited electron transfer, ROS-induced toxicity and interactions between semiconductors and bacteria. Pristine semiconductors such as metal oxides (TiO₂ and ZnO) have been widely reported; however, they suffer some drawbacks such as narrow optical response and high photogenerated carrier recombination. Herein, some typical modification strategies will be discussed including noble metal doping, ion doping, hybrid heterojunctions and dye sensitization. Besides, the biosafety and biocompatibility issues of semiconductor materials are also considered for the evaluation of their potential for further biomedical applications. Furthermore, 2D materials have become promising candidates in recent years due to their wide optical response to NIR light, superior antibacterial activity and favorable biocompatibility. Besides, the current research limitations and challenges are illustrated to introduce the appealing directions and design considerations for the future development of photocatalytic semiconductors for antibacterial applications.

A review on graphitic carbon nitride (g-C3N4) based hybrid membranes for water and wastewater treatment

Graphitic carbon nitride (g-C₃N₄) has gained enormous attention for water and wastewater treatment. Compared with g-C₃N₄ nanopowders, g-C₃N₄ based hybrid membranes have demonstrated great potential for its superior practicability. This review outlines the preparation and characterization of g-C₃N₄ based hybrid membranes and presents their representative applications in water and wastewater treatment (e.g., removal of organic dyes, phenolic compounds, pharmaceuticals, salt ions, heavy metals, and oils). Meanwhile, g-C₃N₄ based films for the removal of contaminants through photocatalytic degradation is also summarized. In addition, the corresponding mechanisms and relevant findings are discussed. Finally, the challenges and research needs in the future and application of g-C₃N₄ based hybrid membranes are highlighted.

Recent advances in graphite carbon nitride-based nanocomposites: structure, antibacterial properties and synergies

Bacterial infections and transmission threaten human health and well-being. Graphite carbon nitride (g-C₃N₄), a promising photocatalytic antibacterial nanomaterial, has attracted increasing attention to combat bacterial transmission, due to the outstanding stability, high efficiency and environmental sustainability of this material. However, the antibacterial efficiency of g-C₃N₄ is affected by several factors, including its specific surface area, rapid electron/hole recombination processes and optical absorption properties. To improve the efficiency of the antibacterial properties of g-C₃N₄ and extend its range of applications, various nanocomposites have been prepared and evaluated. In this review, the advances in amplifying the photocatalytic antibacterial efficiency of g-C₃N₄-based nanocomposites is discussed, including different topologies, noble metal decoration, non-noble metal doping and heterojunction construction. The enhancement mechanisms and synergistic effects in g-C₃N₄-based nanocomposites are highlighted. The remaining challenges and future perspectives of antibacterial g-C₃N₄-based nanocomposites are also discussed.

1,4,5,8-Naphthalene tetracarboxylate dianhydride/g-C3N4 van der Waals heterojunctions exhibit enhanced photochemical H2O2 production and antimicrobial activity

Organic semiconductors, including graphitic carbon nitride (g-C₃N₄, CN), represent an important class of materials for the development of novel antimicrobial or biomedical technologies. Of principal interest is the ability of these materials to catalyze the reduction of elemental oxygen to generate reactive oxygen species (ROS), including hydrogen peroxide (H₂O₂). Here, we describe the fabrication of photoactive van der Waals heterojunctions incorporating 1,4,5,8-naphthalene tetracarboxylic dianhydride (NTCDA) and CN. The composite heterojunction systems were characterized by a combination of physical (TEM, SEM, pXRD), spectroscopic (FT-IR, XPS, DRUV, photoluminescence, TCSPC) and kinetic experiments. Electronic interactions between the two components of the heterojunction increase the rate of photochemical production of H₂O₂ from elemental oxygen by 410%, relative to samples of pure CN. Mechanistic analysis reveals that interaction of NTCDA with the surface of CN modifies the mechanism of H₂O₂ formation in the heterojunction photocatalysts. The photochemical production of H₂O₂ by irradiation of the most active heterojunction composition is sufficient to reduce the viability of E. coli O157:H7, S. aureus and Ps. aeruginosa PAO1 by 99%. Importantly, H₂O₂ production by the NTCDA/CN heterojunctions suppresses Ps. aeruginosa biofilm formation, even at light exposure doses that had a lesser impact on overall planktonic cell growth.

Surface adsorbed 1,4,5,8-naphthalene tetracarboxylate dianhydride molecules accept photoexcited electrons from the organic semiconductor g-C₃N₄ to promote formation of H₂O₂ from elemental oxygen and enhance antimicrobial activity.

Linear piezoresistive strain sensor based on graphene/g-C3N4/PDMS heterostructure

Here we report a novel hybrid material consists of 2D graphitic carbon nitride (g-C₃N₄) and graphene heterostructure that exhibits piezoresistivity superior to graphene and potentially being used as a strain sensor. The g-C₃N₄ that contains periodically spaced triangular nanopores is used for improving the piezoresistivity of the sensor imparting change in the polarization upon application of strain. In this work, we have investigated graphene/g-C₃N₄ interfaced materials and quantified its piezoresistive effects through experimental analysis and density functional theory (DFT) based computational studies provide insights into the electronic structures of the hybrid interfaces. We have observed a linear response in electrical resistance for a wide range of uniaxial strains up to ∼25%. The observed increase in resistance upon application of strain corroborates with our computational finding of strain-dependent band gap opening. Further, it has been realized that band-gap opening occurs exclusively in the graphitic layer of the composite materials under strain. However, the g-C₃N₄ bands remain intact at the interface. The linearity and a considerably small gauge factor (1.89) make graphene/g-C₃N₄ a promising heterostructure material unlike conventional metal gauge sensor in wide strain pressure sensor devices.

Development of Photoactive g-C3N4/Poly(vinyl alcohol) Composite Hydrogel Films with Antimicrobial and Antibiofilm Activity

Free-standing, composite hydrogels containing the visible-light responsive metal-free semiconductor graphitic carbon nitride (g-C₃N₄) as an integral component have been fabricated by direct casting techniques. At 0.67% g-C₃N₄ loading, intermolecular interactions between the semiconductor particles and the PVA polymer chains enhance both the mechanical and photophysical properties of the resulting hydrogels. In contrast, much higher g-C₃N₄ loadings of 3.3 or 6.7% g-C₃N₄ resulted in growth of the average semiconductor particle size and reduction in interactions between the incorporated photocatalyst and the PVA chains. The increased dimensions of the g-C₃N₄ semiconductor particles had the effect of compromising the mechanical properties of the composite system and reducing the lifetime of photogenerated charge carriers. However, the close proximity of g-C₃N₄ particles that is realized at increased semiconductor loading densities improves the absorption cross section of the material, resulting in an overall improvement in the photocatalytic activity of the material. Application of visible radiation caused all of the composite hydrogels to generate hydrogen peroxide (H₂O₂) at catalytic rates of 0.9-2.5 μM/min, while H₂O₂ decomposition rates remained similar across the different preparations. In studies to examine antimicrobial performance, irradiation of 6.7% g-C₃N₄/PVA hydrogel samples with visible radiation (400 ≤ λ ≤ 800 nm) generated sufficient H₂O₂ to significantly reduce both the viable planktonic cell population and biofilm formation in cultures of Pseudomonas aeruginosa.

Face Masks in the New COVID-19 Normal: Materials, Testing, and Perspectives

The increasing prevalence of infectious diseases in recent decades has posed a serious threat to public health. Routes of transmission differ, but the respiratory droplet or airborne route has the greatest potential to disrupt social intercourse, while being amenable to prevention by the humble face mask. Different types of masks give different levels of protection to the user. The ongoing COVID-19 pandemic has even resulted in a global shortage of face masks and the raw materials that go into them, driving individuals to self-produce masks from household items. At the same time, research has been accelerated towards improving the quality and performance of face masks, e.g., by introducing properties such as antimicrobial activity and superhydrophobicity. This review will cover mask-wearing from the public health perspective, the technical details of commercial and home-made masks, and recent advances in mask engineering, disinfection, and materials and discuss the sustainability of mask-wearing and mask production into the future.

Size-Dependent in Vitro Biocompatibility and Uptake Process of Polymeric Carbon Nitride

Polymeric carbon nitride (PCN), which demonstrates unique properties, has been widely explored, mostly in photocatalysis; however, the evaluation of its biocompatibility is still needed. Herein, the cytocompatibility of PCN with different lateral size distributions (A-PCN with 160 nm, B-PCN with 20 nm, and C-PCN with 10 nm dominating lateral sizes) was investigated. The viability of three cell lines (L929, MCF-7, and HepG2) has been determined using cell counting kit-8 (CCK-8), neutral red uptake (NRU), and lactate dehydrogenase (LDH) leakage assays. It was found that the highest cytotoxicity of PCN was observed for flakes with a lateral size of ∼20 nm (B-PCN) in three cell lines after 48 h of exposition. The uptake process of B-PCN sheets labeled with fluorescein isothiocyanate (FITC) by cells was also the most effective. Confocal laser scanning microscopy and atomic force microscopy revealed the nanomaterial distribution throughout the cytoplasm and perinuclear region. The results demonstrated the correlation among size, internalization process, and cytocompatibility of the tested polymeric carbon nitride structures.

Antibacterial Carbon-Based Nanomaterials

The emergence and global spread of bacterial resistance to currently available antibiotics underscore the urgent need for new alternative antibacterial agents. Recent studies on the application of nanomaterials as antibacterial agents have demonstrated their great potential for management of infectious diseases. Among these antibacterial nanomaterials, carbon-based nanomaterials (CNMs) have attracted much attention due to their unique physicochemical properties and relatively higher biosafety. Here, a comprehensive review of the recent research progress on antibacterial CNMs is provided, starting with a brief description of the different kinds of CNMs with respect to their physicochemical characteristics. Then, a detailed introduction to the various mechanisms underlying antibacterial activity in these materials is given, including physical/mechanical damage, oxidative stress, photothermal/photocatalytic effect, lipid extraction, inhibition of bacterial metabolism, isolation by wrapping, and the synergistic effect when CNMs are used in combination with other antibacterial materials, followed by a summary of the influence of the physicochemical properties of CNMs on their antibacterial activity. Finally, the current challenges and an outlook for the development of more effective and safer antibacterial CNMs are discussed.

Porous Carbon Networks Derived From Graphitic Carbon Nitride for Efficient Oxygen Reduction Reaction

Great efforts have been dedicated to finding economic and efficient oxygen reduction reaction (ORR) for fuel cell technology. Among various catalysts, N-doped carbon-based nanomaterials have attracted much attention due to low-cost, noble metal free, and good durability. Herein, we developed a facile and economic strategy to prepare nitrogen-doped carbon networks for efficient ORR application. The g-C₃N₄ is used as the template and N source, and dopamine is used as the carbon source. By simple hydrothermal treatment and sintering, N-doped carbon network structures with high specific surface area, effective ORR activity, and superior durability could be acquired. The present strategy is free of involving generally multistep, poisonous reagents, and complication of removing template for fabrication of 3D carbon structures.

Graphitic carbon nitride (g-C3N4)-based photocatalysts for water disinfection and microbial control: A review

Microbial contamination in drinking water is of great concern around the world because of high pathogenic risks to humans. Semiconductor photocatalysis has aroused an increasing interest as a promising environmental remediation technology for water disinfection and microbial control. Among various photocatalysts, graphitic carbon nitride (g-C₃N₄), as a fascinating two-dimensional conjugated polymer consisting of low-cost, earth-abundant elements, has drawn broad attention as a robust, metal-free, and visible-light-active material in the fields of both environmental remediation and solar energy conversion. Photocatalytic applications of g-C₃N₄-based nanomaterials for water splitting, hydrogen production, carbon dioxide reduction, and pollutant degradation have been extensively investigated and systematically reviewed. In contrast, their antimicrobial properties have been explored more recently due to the complex structure and unique metabolism of living microorganisms compared with chemicals. The corresponding rapidly increasing research efforts in the last five years have inspired us to conduct the review. This review is the first to comprehensively summarize the progress in design and antimicrobial performance of g-C₃N₄-based photocatalysts for water disinfection and microbial control, involving not only bacteria but also viruses and microalgae. Moreover, the underlying inactivation mechanisms of photocatalysts for microorganisms are evaluated to provide further understanding of g-C₃N₄-based advanced disinfection processes. In addition, some exciting future opportunities and challenges at the forefront of this research platform are pointed out. It is expected that this review can pave a new avenue for the development of a facile, cost-effective, environmental-friendly, and sustainable disinfection alternative.

Review of global sanitation development

The implementation of the United Nations (UN) Millennium Development Goals (MDGs) and Sustainable Development Goals (SDGs) has resulted in an increased focus on developing innovative, sustainable sanitation techniques to address the demand for adequate and equitable sanitation in low-income areas. We examined the background, current situation, challenges, and perspectives of global sanitation. We used bibliometric analysis and word cluster analysis to evaluate sanitation research from 1992 to 2016 based on the Science Citation Index EXPANDED (SCI-EXPANDED) and Social Sciences Citation Index (SSCI) databases. Our results show that sanitation is a comprehensive field connected with multiple categories, and the increasing number of publications reflects a strong interest in this research area. Most of the research took place in developed countries, especially the USA, although sanitation problems are more serious in developing countries. Innovations in sanitation techniques may keep susceptible populations from contracting diseases caused by various kinds of contaminants and microorganisms. Hence, the hygienization of human excreta, resource recovery, and removal of micro-pollutants from excreta can serve as effective sustainable solutions. Commercialized technologies, like composting, anaerobic digestion, and storage, are reliable but still face challenges in addressing the links between the political, social, institutional, cultural, and educational aspects of sanitation. Innovative technologies, such as Microbial Fuel Cells (MFCs), Microbial Electrolysis Cells (MECs), and struvite precipitation, are at the TRL (Technology readiness levels) 8 level, meaning that they qualify as "actual systems completed and qualified through test and demonstration." Solutions that take into consideration economic feasibility and all the different aspects of sanitation are required. There is an urgent demand for holistic solutions considering government support, social acceptability, as well as technological reliability that can be effectively adapted to local conditions.

Urea-derived graphitic carbon nitride (u-g-C3N4) films with highly enhanced antimicrobial and sporicidal activity

In this manuscript, we describe the fabrication of photoactive biocidal or sporicidal films from urea-derived graphitic carbon nitride (u-g-C₃N₄). Co-deposited films of u-g-C₃N₄ and Escherichia coli O157:H7 (IC₅₀=14.1±0.2mJ) or Staphylococcus aureus (methicillin resistant IC₅₀=33.5±0.2mJ, methicillin sensitive IC₅₀=42.7±0.5mJ) demonstrated significantly enhanced bactericidal behavior upon administration of visible radiation (400nm≤λ≤426nm). In all cases, complete eradication of the microbial sample was realized upon administration of 100mJ of visible radiation, while no antimicrobial activity was observed for non-irradiated samples. In contrast, Bacillus anthracis endospores were more resistant to u-g-C₃N₄ mediated killing with only a ca. 25% reduction in spore viability when treated with a 200mJ dose of visible radiation. Characterization of u-g-C₃N₄ reveals that the improved activity results from enhancements of both the surface area and reduction potential of the material's conduction band edge, coupled with fast injection of charge carriers into localized states and a decline in radiative recombination events. The results of this study demonstrate that g-C₃N₄-based materials offer a viable scaffold for the development of new, visible light driven technologies for controlling potentially pathogenic microorganisms.