Nano-Polycrystalline Cu Layer Interlaced with Ti3+-Self-Doped TiO2 Nanotube Arrays as an Electrocatalyst for Reduction of Nitrate to Ammonia.

The electrochemical nitrate reduction reaction (NO3RR) is considered as a promising strategy to degrade nitrate-containing wastewater and synthesize recyclable ammonia at atmospheric pressure and room temperature. In this work, the copper oxides-derived nano-polycrystalline Cu (NPC Cu) was integrated with Ti3+-self-doped TiO2 nanotube arrays (NTA) to fabricate the NPC Cu/H-TiO2 NTA. Ti3+-self-doped TiO2 NTAs and the NPC Cu facilitate electron transfer and mass transportation and create abundant active sites. The unique nanostructure in which Cu nano-polycrystals interlace with the TiO2 nanotube accelerates the electron transfer from the substrate to surface NPC Cu. The density functional theory calculations confirm that the built-in electric field between Cu and TiO2 improves the adsorption characteristic of the NPC Cu/H-TiO2 NTA, thereby converting the endothermic NO3- adsorption step into an exothermic process. Therefore, the high NO3- conversion of 98.97%, the Faradic efficiency of 95.59%, and the ammonia production yield of 0.81 mg cm-2 h-1 are achieved at -0.45 V vs reversible hydrogen electrode in 10 mM NaNO3 (140 mg L-1)-0.1 M Na2SO4. This well-designed NPC Cu/H-TiO2 NTA as an effective electrocatalyst for the 8e- NO3RR possesses promising potential in the applications of ammonia production.

Electrochemically controlled ON/OFF switching of NaBH4 hydrolysis based on NiMoN@NC for on-demand hydrogen production.

A facile and novel electrochemically controlled ON/OFF switching of NaBH4 hydrolysis is proposed for on-demand hydrogen production. A low potential can activate the catalyst to the ON state by promoting the adsorption and hydrolysis of BH4-, while a high potential can deactivate the catalyst to the OFF state by inhibiting the chemical hydrolysis.

Rapid hemostasis and high bioactivity cerium-containing mesoporous bioglass for hemostatic materials.

A two-step-acid-catalyzed-self-assembly method was used to prepare cerium-containing mesoporous bioactive glass with P123 as a template. The results showed that MBG without cerium and MBG with cerium slightly affected its surface area, and its water absorption rate was significantly higher. In vitro coagulation experiments showed that Ce-MBG significantly reduces prothrombin time (PT) and activated partial thromboplastin time (APTT), indicating that MBG containing Ce could promote coagulation and platelet adhesion compared with MBG. These suggested that Ce-MBG may be a good dressing with hemostatic properties, which could shorten the bleeding time of the wound and control the bleeding.

Carbon Coated and Nitrogen Doped Hierarchical NiMo-Based Electrocatalysts with High Activity and Durability for Efficient Borohydride Oxidation.

Sodium borohydride is a promising candidate as hydrogen storage material. The direct borohydride fuel cell (DBFC) as an energy conversation device has attracted intensive attention owing to the low theoretical potential of borohydride oxidation reaction (BOR, -1.24 V vs SHE) on the anode. In this paper, the hierarchical sea urchin-like NiMoN@NC coated by thin carbon layer with optimal BH4- adsorption characteristic was synthesized as a superior electrocatalyst toward BOR. In 1 M NaOH-0.05 M NaBH4, the BOR working potentials are only -55 and 44 mV at the current densities of 10 and 200 mA cm-2 on NiMoN@NC, respectively. Furthermore, the membrane-free DBFC using NiMoN@NC as anodic electrocatalyst shows a maximum power density of 67 mW cm-2 at room temperature with appreciative stability. This well-designed carbon coated and nitrogen doped transition-metal material with hierarchical nano/microstructure as a highly efficient electrocatalyst shows promising potential and bright prospects in electrocatalysis research and practical application for energy conversion systems of DBFC.