No abstract

Although Fenton-like reactions have been extensively used to treat various organic contaminants in wastewaters (oily wastewaters, landfill leachate, denitrification with Fenton oxidized non-degradable large molecular organic pollutants, and removal of phosphorus, etc.), the difficulty in catalyst recovery and the instability of catalytic activity limit their practical application. Herein, iron atoms were inserted in a metal-organic framework (FeNC) with dual reaction sites as highly reactive and stable electro-Fenton-like catalysts for the catalytic oxidation of organic pollutants via the electro-Fenton-like activation reaction of peroxymonosulfate (PMS) with fractional leaching of metal ions. Experiments and density functional theory (DFT) calculations indicate that FeNC with FeN4 and Fe–Fe active sites can rapidly deliver electrons for PMS dissociation. Further, an electrolysis reactor was constructed for the on-site generation of reactive oxygen species, which can stably and continuously purify various organic wastewaters. The combined use of an electrolysis reactor and magnetic catalyst in the current study provides a direction for the long-term remediation of organic pollutants on an industrial scale.

Atmospheric water harvesting is considered a viable source of freshwater to alleviate water scarcity in an arid climate. Water condensation tends to be more efficient on superhydrophobic surfaces as the spontaneous coalescence‐induced droplet jumping on superhydrophobic surfaces enables faster condensate removal. However, poor water nucleation on these surfaces leads to meager water harvest. A conventional approach to the problem is to fabricate micro‐ and nanoscale biphilic structures. Nonetheless, the process is complex, expensive, and difficult to scale. Here, the authors present an inexpensive and scalable method based on manipulating the water‐repellent coatings of superhydrophobic surfaces. Flexible siloxane can facilitate water nucleation, while a branched structure promotes efficient droplet jumping. Moreover, ToF‐SIMS analysis indicated that branched siloxane provides a better water‐repellent coating coverage than linear siloxane and the siloxanes comprise hydrophilic and hydrophobic molecular segments. Thus, the as‐prepared superhydrophobic surface, TiO2 nanorods coated with branched siloxanes harvested eight times more water than a typical fluoroalkylsilane (FAS)‐coated surface under a low 30% relative humidity and performed better than most reported biphasic materials.