Enhanced photocatalytic and antibacterial activities of S-scheme SnO2/Red phosphorus photocatalyst under visible light

Magnetic composite photocatalyst NiFe₂O₄/ZnIn₂S₄/biochar for efficient removal of antibiotics in water under visible light: Performance, mechanism and pathway

The widespread presence of antibiotics in aquatic environments, resulting from excessive use and accumulation, has raised significant concerns. A NiFe₂O₄/ZnIn₂S₄/Biochar (NFO/ZIS/BC) magnetic nanocomposite was successfully synthesized, demonstrating significantly enhanced electron-hole separation properties. Comprehensive investigations were conducted to evaluate the impact of various parameters, including catalyst mass, pH, and the presence of co-existing ions on the composite's performance. The nanoparticles of NiFe₂O₄ (NFO) and ZnIn₂S₄ (ZIS) were found to improve the surface stability and sulfamethoxazole removal capabilities of porous biochar, while also demonstrating high total organic carbon removal efficiencies. •O₂⁻ and h⁺ were identified as the predominant reactive oxygen species (ROS) in NFO/ZIS/BC-4 during the degradation process. The degradation outcomes of sulfamethoxazole under natural sunlight and water conditions were consistent with laboratory findings, affirming the robust applicative potential of NFO/ZIS/BC. Density functional theory (DFT) calculations were performed to elucidate the photocatalytic mechanism and identify potential intermediate products. Additionally, the types of heterojunctions present in the system were characterized and discussed. After multiple iterations, NFO/ZIS/BC-4 maintained effective photodegradation capabilities through five cycles. This study presents an effective method for the treatment of antibiotics in aquatic environments, offering significant potential for environmental applications.

Enhanced performance of dual-functional ZIF-8/red phosphorus photocatalysts for concurrent degradation of organic dyes and hydrogen generation under natural solar light irradiation

Herein, zeolitic imidazole framework (ZIF)-8/red phosphorus photocatalysts were prepared via a solvothermal method for simultaneous organic dye degradation and hydrogen (H2) generation. The 5 wt% ZIF-8/RP photocatalyst achieved the highest H2 generation rate of 822.5 μmol h-1 g-1 and 92% rhodamine dye degradation under natural sunlight irradiation. This approach offers an effective strategy to replace costly and toxic traditional electron donors with organic dye pollutants for H2 generation.

CuInS2/Red Phosphorus Nanosheet Interleaved Heterostructures with Improved Interfacial Charge Transfer for Photoelectrochemical Aptasensing

Accelerating the migration of interfacial carriers in heterojunctions is crucial for achieving highly sensitive photoelectrochemical (PEC) sensing. In this study, we developed three-dimensional (3D)/two-dimensional (2D) CuInS2/red phosphorus nanosheet (CuInS2/RP NS) n-n heterojunction functional materials with enhanced interfacial charge transfer capabilities for PEC sensing. The 3D CuInS2 serves as a conductive layer, providing excellent electronic conductivity and superior electron absorption and transport properties. In contrast, the ultrathin RP NS acts as a transport layer that enhances carrier mobility. The 3D/2D heterojunction ensures a large interface contact surface, shortening the carrier transport distance. A well-aligned band position generates a substantial built-in electric field, providing a significant driving force for efficient carrier separation and migration, thereby improving response sensitivity. A PEC aptamer sensor was constructed based on the synthesized heterostructure for ciprofloxacin detection. The detection limit of the CuInS2/RP NS aptamer sensor for ciprofloxacin is 2.03 × 10-15 mg·mL-1, with a linear range from 1.0 × 10-14 to 1.0 × 10-5 mg·mL-1. This work presents a strategy for enhancing the photoelectric response by modulating the interface structure of heterojunctions, thereby opening new prospects for the application of highly sensitive PEC sensors in antibiotic detection.

The loading of Fe ions on N-doped carbon nanosheets to boost photocatalytic cascade for water disinfection

The pervasive presence of pathogenic bacteria in water environment poses a serious threat to public health. Here, a photocatalytic cascade was developed to reveal great water disinfection. Firstly, N-doped carbon nanosheets (N-CNSs) about 30-50 nm in size were synthesized by a hydrothermal strategy. It revealed wide-spectrum photocatalysis for H2O2 generation via a typical two-step single-electron process. A Fenton agent (Fe ion) was loaded, N-CNSs-Fe can in-situ convert photocatalytic H2O2 into ·OH with high oxidation potential. Moreover, its Fenton active is three times greater than pure Fe2+ owing to electron enrichment from N-CNSs to Fe for Fe3+/Fe2+ cycle. Further investigation displayed that Fe loading also could decrease bad gap and promote charge separation to boost photocatalysis. In addition, N-CNSs-Fe possesses positive surface potential to exhibit strong interaction with negative bacteria, facilitating the capture. Therefore, the nanocomposite can effectively inactivate E. coli with a lethality rate of 99.7 % under stimulated sunlight irradiation. In addition, it also was employed to treat a complex lake water sample, revealing great antibacterial (95.1 %) and dye-decolored (92.3 %) efficiency at the same time. With novel biocompatibility and antibacterial ability, N-CNSs-Fe possessed great potential for water disinfection.

One-pot synthesis of 2D Ag/BiOCl/Bi2O2CO3 S-scheme heterojunction with oxygen vacancy for photocatalytic disinfection of Fusarium graminearum in vitro and in vivo

2D Ag/BiOCl/Bi₂O₂CO₃ S-scheme heterojunction was prepared with oxygen vacancy (OVs) via one-pot hydrothermal method. The XRD and XPS analysis indicated the synthesized sample contained Ag nanoparticles (AgNPs) instead of Ag ions. The SEM and HRTEM pictures showed that BiOCl/Bi₂O₂CO₃ nanosheets were modified with AgNPs. Compared with AgNPs, BiOCl, and Bi₂O₂CO₃, Ag/BiOCl/Bi₂O₂CO₃ exhibited highly photocatalytic inactivation of pathogenic fungi (Fusarium graminearum) due to the wide light absorption range and S-scheme heterojunction structure, which improved the production and transfer of photogenerated carrier, and enhanced the separation of photogenerated e-/h⁺ pairs. In addition, the improved photocatalytic disinfection against Fusarium graminearum of Ag/BiOCl/Bi₂O₂CO₃ was verified in Sedeveria Letizia plant. Furthermore, active species capture assay and ESR experiments disclosed the involvement of OVs, h⁺, ∙O₂^-, ∙OH, and ^-for Fusarium graminearum destruction during photocatalysis process. The S-scheme heterojunction was proved via oxygen vacancy, which was extensively beneficial to increase charge transmission and separation efficiency. Our work proposed Ag/BiOCl/Bi₂O₂CO₃ was an efficient and ecological fungicide to inactive Fusarium graminearum in vitro and vivo for crop disease.

A PPy/MoS2 core–shell heterojunction modified by carbon dots exhibits high photocatalytic antibacterial performance

CQDs and PPy facilitate the separation of MoS2 electron–hole pairs and enhance their photocatalytic antibacterial performance.