Hierarchical BiOBr microspheres with oxygen vacancies synthesized via reactable ionic liquids for dyes removal

Construction of Ag2O-modified g-C3N4 photocatalyst for rapid visible light degradation of ofloxacin

The design of stable and highly efficient photocatalysts had emerged as an economic and promising way for eliminating harmful pharmaceutical pollutants. In this study, a series of Ag₂O-modified g-C₃N₄ composites with different Ag₂O amounts (denoted as Ag₂O-CN_x) were fabricated via a facile reflux condensation methodology. Ofloxacin (OFL) was chosen as a model pollutant to evaluate the degradation efficiency of the photocatalytic system. The optimal photocatalytic activity was achieved with Ag₂O-CN_1.0, which reached up to 99.1% removal of OFL after 15-min reaction and the pseudo-first-order constant was 0.469 min^-1, approximately 42 times higher than that of g-C₃N₄. Considering the complexity of the actual environment, the important influential factors such as catalyst dosage, initial OFL concentration, solution pH, and natural organic matter on the OFL degradation were systematically investigated. Additionally, Ag₂O-CN_1.0 showed good stability and recyclability in multiple cycle experiments. The feasible photodegradation mechanism of OFL was proposed with radical scavenger experiments, and the degradation products were determined. Furthermore, the enhanced photocatalytic activity could be ascribed to not only the high photogenerated charge separation efficiency and the surface plasmon resonance effect of metallic Ag, but also the p-n heterojunction formed between Ag₂O and g-C₃N₄. Therefore, Ag₂O-CN_1.0 was a treatment material possessing great application prospects for eliminating OFL in wastewater.

Friction energy harvesting on bismuth tungstate catalyst for tribocatalytic degradation of organic pollutants

Mechanical energy as the green and sustainable energy source widely distributes in natural environment. In this paper, we successfully realize the conversion of mechanical energy through a friction route on the tribocatalyst of Bi₂WO₆. Under magnetic stirring, the friction between the PTFE-sealed magnetic bar and the catalyst particles resulted in the electron transfer crossing the contact interface, in which PTFE accepted the electrons and simultaneously the holes were left on the catalyst. The positively charged catalyst was demonstrated through electrostatic attraction and repulsion tests. Like photocatalytic process, the holes on the valence band of Bi₂WO₆ have strong oxidative ability that can efficiently oxidize organic pollutants. The tribocatalytic tests showed that the Bi₂WO₆ could eliminate organic dyes under magnetic stirring in dark, and we could further optimize the tribocatalytic performance via regulating the size of magnetic bar and reactor material. Finally, a high stability of tribocatalysis was revealed by the multiple tests. This work not only develops a green tribocatalysis strategy to oxidative purification of organic pollutants, but also provides a possible pathway to convert mechanical energy in environment to chemical energy, such as potential applications in environmental remediation and sustainable energy.

Nano-engineered Adsorbent for the Removal of Dyes from Water: A Review

Background:

The huge quantity of wastewater, containing poisonous and hazardous dyes, is released by various industries which pollute water in direct and indirect ways. Most of the dyes are a dangerous class of water contaminants which have affected the environment drastically. Some dyes such as congo red, rhodamine B, methylene blue, methyl violet, and crystal violet are a serious threat to human beings.

Remediation Method:

Numerous methods are available for the removal of dyes from water. Adsorption, being a superior and eco-friendly technique, has advantage of eliminating organic dyes because of the availability of materials as adsorbents. The inexpensive nanomaterials are a more attractive choice for remediation of various dyes due to their unique properties and offer an adequate pathway to adsorb any organic dye from water to overcome its hazardous effects on human health.

Results:

In this review, we have discussed the latest literature related to various types of synthesis, characterization and uses as adsorbent for highly adsorptive removal capacity of nanoparticles for organic dyes.

Conclusion:

Adsorption technology provides an attractive pathway for further research and improvement in more efficient nanoparticles, with higher adsorption capacity, for numerous dyes to eliminate the dyes discharged from various industries and thus reduce the contamination of water. Therefore, nanocomposites may contribute to future prospective water treatment process.

A visible-light driven novel layered perovskite oxyhalide Bi4MO8X (M = Nb, Ta; X = Cl, Br) constructed using BiOX (X = Cl, Br) for enhanced photocatalytic hydrogen evolution

A novel visible-light responsive layered perovskite photocatalyst Bi₄MO₈X (M = Nb, Ta; X = Cl, Br) has been successfully constructed using BiOX (X = Cl, Br) via a solid state method.