Solution Blow Spinning Ultrafine Fiber Sponge-Loaded MOF-808 for Effective Adsorption and Degradation of Mustard Gas.

Functional materials that can quickly absorb and degrade mustard gas are essential for chemical warfare emergency response kits. In this study, a fiber membrane with excellent adsorption and catalytic degradation activity was developed by solution blow spinning polystyrene (PS)/polyurethane (PU) and hydrothermal in situ growth of a zirconium-based MOF (MOF-808). The mechanical properties of the PS/PU fibers were improved by adding a trimethylolpropane tris (2-methyl-1-aziridine propionate) (TTMA) cross-linking agent. Moreover, the C═O bonds in TTMA provided abundant growth sites for MOF-808 in the hydrothermal process, thereby greatly increasing the loading capacity. The fiber surface was completely covered with the MOF-808 particles within 24 h. The PS/PU/TTMA/MOF-808 fiber membrane was used for the catalytic degradation of 2-chloroethyl ethyl sulfide (CEES). The degradation efficiency reached 97.7% after 72 h, indicating its great application potential in emergency wiping cloths for mustard gas adsorption and degradation.

Hydrogen evolution reaction catalysis on RuM (M = Ni, Co) porous nanorods by cation etching.

The development of efficient and stable nanomaterial electrocatalysts for the hydrogen evolution reaction (HER) is of great significance for renewable energy conversion via water electrolysis. Herein, we have developed a novel class of bimetallic RuM (M = Ni, Co) hollow nanorods (HNRs) through a facile Fe3+ etching strategy, as electrocatalysts for enhancing the HER. Morphological physical characterization and electrochemical tests demonstrated that RuM (M = Ni, Co) HNRs with hollow structures can effectively enhance electrocatalytic activity due to their high specific surface areas. Impressively, the RuNi HNRs exhibited superior HER performance with an overpotential of merely 25.6 mV in 1 M KOH solution at 10 mA cm-2, which is significantly lower than that of commercial Pt/C (44.7 mV). Moreover, the as prepared RuNi HNRs showed excellent stability and could continuously work at a current density of 10 mA cm-2 for 40 h with a negligible increase in potential. The Ru-based HNRs also showed high HER activity in an acidic solution. This study paves a new way for the universal fabrication of bimetallic hollow structured nanomaterials as efficient electrocatalysts for boosting the HER.

Self-driven Ru-modified NiFe MOF nanosheet as multifunctional electrocatalyst for boosting water and urea electrolysis.

Urea electro-oxidation reaction (UOR) has been a promising strategy to replace oxygen evolution reaction (OER) by urea-mediated water splitting for hydrogen production. Naturally, rational design of high-efficiency and multifunctional electrocatalyst towards UOR and hydrogen evolution reaction (HER) is of vital significance, but still a grand challenge. Herein, an innovative 3D Ru-modified NiFe metal-organic framework (MOF) nanoflake array on Ni foam (Ru-NiFe-x/NF) was elaborately designed via spontaneous galvanic replacement reaction (GRR). Notably, the adsorption capability of intermediate species (H*) of catalyst is significantly optimized by Ru modification. Meanwhile, rich high-valence Ni active species can be acquired by self-driven electronic reconstruction in the interface, then dramatically accelerating the electrolysis of water and urea. Remarkably, the optimized Ru-NiFe-③/NF (1.6 at% of Ru) only requires the overpotential of 90 and 310 mV to attain 100 mA cm-2 toward HER and OER in alkaline electrolyte, respectively. Impressively, an ultralow voltage of 1.47 V is required for Ru-NiFe-③/NF to deliver a current density of 100 mA cm-2 in urea-assisted electrolysis cell with superior stability, which is 190 mV lower than that of Pt/C-NF||RuO2/NF couple. This work is desired to explore a facile way to exploit environmentally-friendly energy by coupling hydrogen evolution with urea-rich sewage disposal.

General fabrication of RuM (M = Ni and Co) nanoclusters for boosting hydrogen evolution reaction electrocatalysis.

Rational design and fabrication of highly active electrocatalysts toward the hydrogen evolution reaction (HER) are of paramount significance in industrial hydrogen production via water electrolysis. Herein, by taking advantage of the high surface-to-volume ratio, maximized atom-utilization efficiency, and quantum size effect, we have successfully fabricated an innovative class of Ru-based alloy nanoclusters. Impressively, carbon fiber cloth (CFC) supported RuNi nanoclusters could exhibit outstanding electrocatalytic performance toward the HER, in which the optimal composition RuNi/CFC could achieve a current density of 10 mA cm-2 with an overpotential of merely 43.0 mV in 1 M KOH electrolyte, as well as a low Tafel slope of 30.4 mF dec-1. In addition to the high HER activity in alkaline media, such Ru-based alloy nanoclusters are also demonstrated to be highly active and stable in acidic solution. Mechanistic studies reveal that the alloying effect facilitates water dissociation and optimizes hydrogen adsorption and desorption, thereby contributing to the outstanding HER performance. This work paves a new way for the rational fabrication of advanced electrocatalysts for boosting the HER.

Universal MOF-Mediated synthesis of 2D CoNi-based layered triple hydroxides electrocatalyst for efficient oxygen evolution reaction.

Developing low-budget, stable, and high-performance electrocatalyst toward oxygen evolution reaction (OER) is of pivotal significance in the fields of energy conversion and storage. Herein, a universal metal organic framework (MOF)-mediated method for the synthesis of two-dimensional (2D) layered triple hydroxides (LTHs) nanosheets with ultrathin nature has been developed. It is interesting to disclose that the CoNi-based LTHs possess better electrochemical catalytic performance, giving superior performance to commercial RuO2 catalysts. Remarkably, benefitting from the ultrathin nanosheet configuration, optimized electronic structure, and strong synergistic effect, the optimized CoNiFe LTHs nanosheets show excellent OER performance with an ultralow overpotential of 262 mV at a current density of 10 mA cm-2 and a small Tafel slope of 88.1 mV dec-1. This work provides a promising avenue to develop low-cost and high-performance layered ternary hydroxide electrocatalysts.

PtM/Mx By (M=Ni, Co, Fe) Heterostructured Nanobundles as Advanced Electrocatalyst for Hydrogen Evolution Reaction.

Optimizing the electronic and synergistic effect of hybrid electrocatalysts based on Pt and Pt-based nanocatalysts is of tremendous importance towards a superior hydrogen evolution performance under both acidic and alkaline conditions. However, developing an ideal Pt-based hydrogen evolution reaction (HER) electrocatalyst with moderated electronic structure as well as strong synergistic effect is still a challenge. Herein, we fabricated boron (B)-doped PtNi nanobundles by a two-step method using NaBH4 as the boron source to obtain PtNi/Ni4 B3 heterostructures with well-defined nanointerfaces between PtNi and Ni4 B3 , achieving an enhanced catalytic HER performance. Especially, the PtNi/Ni4 B3 nanobundles (PtNi/Ni4 B3 NBs) can deliver a current density of 10 mA cm-2 at the overpotential of 14.6 and 26.5 mV under alkaline and acidic media, respectively, as well as outstanding electrochemical stability over 40 h at the current density of 10 mA cm-2 . Remarkably, this approach is also universal for the syntheses of PtCo/Co3 B and PtFe/Fe49 B with outstanding electrocatalytic HER performance.

Tunable long-chains of core@shell PdAg@Pd as high-performance catalysts for ethanol oxidation.

High performance nanomaterial catalysts have attracted great attention on the application for the direct alcohol fuel cell. To improve the catalytic behavior, it is a challenge to modulate the surface structure and morphology of catalysts. We integrated properties of advanced networks nanostructure and core@shell structure to form a series of PdAg@Pd worm-like networks catalysts. Importantly, the composition-optimized Pd76Ag24 WNWs exhibited excellent catalytic performance towards ethanol oxidation reaction compared to that of commercial Pd/C catalysts in alkaline media. The mass activity of Pd76Ag24 WNWs is 3.55 times higher than that of commercial Pd/C catalysts for EOR. Moreover, the Pd76Ag24 WNWs also showed superior stability after 250 successive cycles and kept far higher residual activities than that of the other catalysts. The synthesis of PdAg@Pd worm-like networks catalysts provides a reference to well combine the advantages of core@shell and networks structure to form high performance catalysts application for DEFC.

Ir-Doped Pd Nanosheet Assemblies as Bifunctional Electrocatalysts for Advanced Hydrogen Evolution Reaction and Liquid Fuel Electrocatalysis.

Although great progress in pursuing high-performance catalysts for advanced electrocatalysis has been made, the design of high-efficiency electrocatalysts continues to be a huge challenge for commercializing electrochemical energy technologies. Herein, a three-dimensional (3D) hierarchical assembly nanostructure consisting of ultrathin Ir-doped Pd nanosheets has been well designed, which could serve as a bifunctional electrocatalyst for advanced hydrogen evolution reaction (HER) and liquid fuel electrooxidation. In particular, the optimized Pd83.5Ir16.5 nanocatalyst displays excellent electrocatalytic HER performance with an overpotential of only 73 mV at 10 mA cm-2 along with excellent stability. More importantly, it can also show outstanding electrocatalytic performance for liquid fuel oxidation with a mass activity of 4326.1 mA mgmetal-1 for ethylene glycol oxidation reaction. Mechanistic study reveals that the highly porous 3D nanostructure, the modulation of electronic structure after the introduction of Ir, not only guarantees a high level of exposure of surface active sites and smooth charge transfer but also generates the new active centers for facilitating the adsorption of H2O and recombination of H*, thereby dramatically increasing the intrinsic activity of electrocatalysis.

BiOBr nanoplates@TiO2 nanowires/carbon fiber cloth as a functional water transport network for continuous flow water purification.

A novel BiOBr@TiO2/carbon hybrid framework as a continuous flow sunlight water purification system has been reported in the present work. The BiOBr@TiO2/carbon hybrid framework was fabricated via the sequential growth of TiO2 nanowires and BiOBr nanoplates on carbon fiber cloth. TiO2 nanowires interweaved with carbon fibers to form a porous network, while BiOBr nanoplates were arrayed on TiO2 nanowires. The obtained BiOBr@TiO2/carbon hybrid framework possesses numerous micro/nanochannels between their adjacent one-dimensional building blocks, which can serve as an effective water transport network driven by capillary force. Furthermore, BiOBr@TiO2/carbon hybrid frameworks exhibit impressive sunlight-driven photocatalytic activity and adsorption ability because of their enhanced sunlight absorption ability, efficient charge separation features, and mesoporous architecture. The excellent reusability and durability of the BiOBr@TiO2/carbon hybrid frameworks have also been confirmed. A novel BiOBr@TiO2/carbon hybrid framework based continuous flow sunlight water purification system with a high water purification efficiency (305.6 L h-1 m-2) has been constructed in the present work. All the features make the BiOBr@TiO2/carbon hybrid framework a promising material suitable for water purification.