Catalytic oxidation of toxic organic pollutants in water urgently requires improved efficiency for practical application. Here a wrapping-pyrolysis strategy is exploited to convert CoP nanowires-threaded ZIF-8 into CoP nanoparticlesconfined nitrogen-doped yolk-shell porous carbon polyhedra, featuring highdensity active sites, and high adsorbability, dispersibility and conductivity (4-High). The nanoreactor efficiently activates peroxymonosulfate for bisphenol A (BPA) degradation over a wide pH range and in saline solutions. The apparent kinetic rate constant (18.96 min −1) is the highest reported to date and exceeds those of reported catalysts by 1-2 orders of magnitude. Experimental and theoretical evidence reveals that the catalysis occurs at the Co 4 P 4 @graphitic nitrogen-doped graphene site to produce surface-bound SO 4 •− and induce direct electron abstraction for BPA degradation. The high catalytic activity is attributed to the unique yolk-shell structure which concentrates catalytic and adsorptive sites within a confined space, as well as to the porous carbon polyhedron with high dispersibility and conductivity for fast mass and electron transport. Moreover, a fluidized-bed catalytic unit is constructed and enables continuous zero discharge of BPA and easy nanocatalyst recycling. This work will guide "4-High" catalyst design to improve future deep water purification technology.

The heterogeneous electro-Fenton (EF) process is a promising wastewater treatment technology for the onsite production of H 2 O 2 and avoidance of iron sludge. However, the preparation of the cathode catalysts remains a challenge. Not only must the catalyst surface possesses active sites for both 2e − oxygen reduction reaction and heterogeneous Fenton reaction, preventing active metals from continuous leaching is also crucial to maintain its catalytic activity. Herein, a heterogeneous catalyst (rGO@Fe x P/C) with a vacuumized package-like structure, where carbon-supported iron phosphides (Fe x P/C) are tightly covered within interconnected reduced graphene oxide (rGO) sheets, is successfully prepared. The concentration of iron that dissolved from rGO@ Fe x P/C after the reaction is only 3.37% of bare Fe x P/C (14.6 mg L −1 ), while rGO@Fe x P/C achieves better performance towards sulfamethoxazole (10 mg L −1 ) degradation than Fe x P/C. Investigation on rGO@Fe x P/C with different thicknesses of outer rGO layer and diverse morphologic structures demonstrate that the unique structure of rGO@Fe x P/C played a decisive role in the simultaneously enhanced activity and stability.

Core–shell Fe3O4@polyaniline nanocomposites harvest microwave energy and realize ultrafast Cr(vi) reduction with oxalic acid as a sacrificial electron donor.