Pathogenic contamination is considered to be the most harmful issue worldwide and is responsible for various kinds of waterborne diseases [90]. It is directly responsible for the biofouling of any water filtration membrane; therefore, it is important that a membrane should be tested against antibacterial properties. Up to date, several bactericidal nanomaterials including graphene, TMDCs, and MXenes have been explored to meet these challenges. The antibacterial activity of graphite, graphite oxide, GO, rGO, MoS₂, and WS₂ against Gram-negative and Gram-positive bacteria have already been tested. Recently, MXenes with unique hydrophilic properties, a good adsorption, an ideal surface functionality, and excellent biocompatibility and photothermal properties have been widely tested for wastewater treatment and desalination, water purification, ion separation and other applications, as shown in Table 1. MXenes are expected to be resistant to biofouling and offer bactericidal properties [91]. However, very few studies [91,92,93,94,95,96,97,98,99] have been carried out in this direction. An initial work by Rasool et al. [97] reported that Ti₃C₂Tx membranes could be an ideal platform for antibacterial studies (Figure 5a–d). Rasool et al. [97] further used Ti₃C₂T_x-based membranes to measure the antibacterial properties against Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) by using bacterial growth curves based on optical densities (OD) and colony growth on agar nutritive plates (Figure 5b,c). The membranes showed a high antibacterial efficiency against both Gram-negative E. coli and Gram-positive B. subtilis compared with the GO membranes. Concentration-dependent antibacterial activity was observed and more than 98% of bacterial cell viability loss was found at 200 μg/mL in Ti₃C₂T_x for both bacterial cells within 4 h of exposure, as confirmed by a colony-forming unit (CFU) and regrowth curve (Figure 5d,e). In another study, Ti₃C₂T_x/PVDF composite membranes were tested to measure the antibacterial rate of E. coli and B. subtilis [91]. The composite membranes showed a ~73% and ~63% antibacterial rate for B. subtilis and E. coli, respectively, compared with the control PVDF membranes [91]. Additionally, the Ti₃C₂T_x membrane showed over a 99% growth inhibition of both bacteria under the same conditions. Mayerberger et al. [92] demonstrated Ti₃C₂Tz/chitosan composite nanofiber membranes for a passive antibacterial wound dressing application. The as-prepared composite membrane showed a 95% and 62% reduction in the colony-forming units of Gram-negative E. coli and Gram-positive Staphylococcus aureus (S. aureus), respectively. Jastrzebsa and coworkers also reported the antimicrobial properties of a Ti₃C₂ MXene-based nanocomposite, i.e., Ti₃C₂/SiO₂/Ag, Ti₃C₂/Al₂O₃/Ag, and Ti₃C₂/SiO₂/Pd [93]. They also demonstrated the outstanding bioactive properties of Ti₂C and Ti₃C₂ MXenes against a Gram-negative bacterial strain [99]. Recently, Zhu et al. [95] evaluated the effect of near-infrared (NIR) light on the antibacterial activities of silver (Ag), Ti₃C₂T_x, and an Ag/Ti₃C₂T_x composite. The as-prepared Ag/Ti₃C₂T_x composite showed a high efficacy against Gram-positive S. aureus and Gram-negative E. coli bacteria in an in vitro antibacterial test. Upon NIR irradiation, the antimicrobial effect of Ag/Ti₃C₂T_x significantly strengthened compared with the pristine Ag and Ti₃C₂T_x. The growth of E. coli was completely inhibited during the initial 0–6 h by 200 µg/mL of Ti₃C₂T_x due to the photothermal heat produced killing the bacteria in the surrounding area. The Ag/Ti₃C₂T_x composite exhibited the best antibacterial activities with the same dose of pristine Ag and Ti₃C₂T_x. After NIR irradiation, the Ti₃C₂T_x composite could completely restrain the E. coli growth when used at 100–200 µg/mL.