RESUMEN
Halogen wastewater greatly threatens the health of human beings and aquatic organisms due to its severe toxicity, corrosiveness, and volatility. Efficient bromine removal is therefore urgently required, while existing Br2-capture materials often face challenges from limited water stability and possible halogen leaking. We report a facile and efficient aqueous Br2 removal method using submicron resorcinol-formaldehyde (RF) resin nanoparticles (NPs). The abundant aromatic groups dominate the Br2 removal by substitution reactions. An excellent Br2 conversion capacity of 7441 mg gRF-1 was achieved by RF NPs that outperform state-of-the-art materials by â¼2-fold, along with advantages including good water stability, low cost, and easy fabrication. Two recycling-coupled (electrochemical or H2O2-involved) Br2 removal routes further reveal the feasibility of in-depth halogen removal by RF NPs. The brominated resin can be downstream upcycled for silver recovery, realizing the harvesting of precious metal, reducing of heavy-metal pollution, and resource utilization of brominated resin.
RESUMEN
Aqueous zinc-ion batteries have attracted a continually increasing level of interest for large-scale energy storage because they are highly safe and have high energy density and abundant reserves. However, Zn anodes face significant challenges such as severe dendrite growth and hydrogen evolution reaction (HER). We here propose an efficient Zn2+ sieve strategy for modulating the anode chemistry using two-dimensional NH2-MIL-125 (Ti) metal-organic framework (MOF) nanosheets. Theoretical investigations reveal the crucial role of the Ti MOF in regulating Zn2+ solvation structures for fast diffusion and uniform deposition and decreasing HER reactivity. The structure of the nanosheets enables abundant accessible desolvation sites and shortened ionic pathways. As a result, the MOF nanosheet-protected Zn anode exhibited greatly improved cycling stability in both symmetric cells and full cells. Operando optical monitoring and postmortem analysis revealed effective suppression of dendrite growth and HER by Ti MOF nanosheets. This anti-HER MOF-enabled Zn2+ sieve strategy provides a viable Zn anode and provides new insights for optimizing aqueous batteries.
RESUMEN
Defects engineering has played an ever-increasing important role in electrochemistry, especially secondary lithium batteries. TiO2 is regarded as a promising anode due to its attractive cycling stability, low volume strain and great abundance, while challenges of intrinsic poor electrical and ionic conductivity remain to be addressed. Herein, we report a three-in-one oxygen vacancy (VO)-involved pomegranate design for TiO2-x/C composite anode, which provides highly improved electrical conduction, shortened Li+ pathway and promoted Li+ redox. N-doped mesoporous carbon acts as a robust scaffold to support the whole structure, electron highway and efficient reductant to generate VO on TiO2 nanoparticles during crystallization. Theoretical calculations reveal the crucial role of surface VO on TiO2 in Li electrochemistry. Resultantly, the optimal TiO2-x/C anode achieves significantly enhanced cycling performance (203 mAh/g retained after 2000 cycles at 1 A/g). Postmortem analysis reveals the robustness of VO and reasonable structure stability upon cycles for improved battery performance.