Constructing benzene ring modified graphitic carbon nitride with narrowed bandgap and enhanced molecular oxygen activation for efficient photocatalytic degradation of oxytetracycline

Ternary heterojunction of cross-linked benzene Polymer/Bi2MoO6-Graphene oxide catalysts promote efficient adsorption and photocatalytic removal of oxytetracycline

Antibiotics are refractory degradable organic pollutants that present a significant hazard to water environments. In this work, a ternary composite (KB/BMO-GO) comprising of graphene oxide (GO), Bi2MoO6 (BMO), and a cross-linked benzene polymer (KB) was synthesized and applied to promote the synergistic adsorption-photocatalytic degradation of the refractory pollutant, oxytetracycline (OTC). The inclusion of GO and KB in the composite enhanced the OTC adsorption performance of the catalysts, and the construction of Z-scheme heterojunction promoted the photogenerated charge separation efficiency and broadened the range of light absorption, thereby enhancing the photocatalytic performance. Moreover, we compared the performance of catalysts loaded with different mass ratios of KB (x% KB/BMO-GO). Among them, the 15 % KB/BMO-GO catalyst sample had the best OTC degradation performance. Specifically, 15 % KB/BMO-GO could adsorb 69.7 % of OTC in 30 min, reaching an OTC degradation rate of 93.3 % under visible light irradiation. h+ and 1O2 are the main active substances in the photocatalytic process. In addition, the catalysts are acid-alkali and salt-resistant, as well as good reusability. This study provides a valuable reference for the preparation of highly efficient photocatalysts for synergistic adsorption-photodegradation processes.

Molecular Doping on Carbon Nitride for Efficient Photocatalytic Hydrogen Production

Molecular doping is an innovative approach to modify the electronic configuration of carbon nitride (CN) photocatalysts, enhancing visible light absorption and optimizing the recombination of electron-hole pairs in photocatalytic H2 generation. Unlike the conventional heteroatom incorporation strategy, molecular doping offers a more effective means of structure optimization and conjugated framework. This Perspective studies recent advancements in benzene-ring doping for CN, emphasizing the correlation between structure and photocatalytic activity. The advantages and disadvantages of molecular doping in CN are thoroughly demonstrated, underscoring the importance of utilizing molecular doping to fine-tune both electronic and physical structures for enhanced photocatalytic efficacy. Insights are provided on strategies to address limitations and explore new prospects in the field of molecular doping methodologies.

Stable photodegradation of antibiotics by the functionalized 3D-Bi2MoO6@MoO3/PU composite sponge: High efficiency pathways, optical properties and Z-scheme heterojunction mechanism

The designation and fabrication of heterogeneous photocatalyst with superior redox capability is an important technique for emerging pollutants treatment. In this study, we designed the Z-scheme heterojunction of stable 3D-Bi₂MoO₆@MoO₃/PU, which could not only accelerate the migration and separation in photogenerated carriers, but also stabilize the separation rate of photo-generation carriers. In the Bi₂MoO₆@MoO₃/PU photocatalytic system, 88.89% of oxytetracycline (OTC, 10 mg L^-1) and 78.25%-84.59% of multiple antibiotics (SDZ, NOR, AMX and CFX, 10 mg L^-1) could be decomposed within 20 min under the optimized reaction condition, revealing the superior performance and potential application value. Specifically, the morphology, chemical structure and optical properties detection of Bi₂MoO₆@MoO₃/PU greatly affected the direct Z-scheme electron transferring mode in the p-n type heterojunction. Besides, the ·OH, h⁺, ·O₂^- dominated the photoactivation process through ring-opening, dihydroxylation, deamination, decarbonization and demethylation in OTC decomposition. Expectantly, the stability and universality of Bi₂MoO₆@MoO₃/PU composite photocatalyst would further broaden the practical application and demonstrated that the potential of photocatalytic technique in antibiotics pollutants for wastewater remediation.