Tianli Wu

3D structured porous CoP3 nanoneedle arrays as an efficient bifunctional electrocatalyst for the evolution reaction of hydrogen and oxygen

Self-supported porous cobalt poly-phosphide nanoneedle arrays on carbon fiber paper (CoP3 NAs/CFP) are fabricated via topotactic phosphidation of the Co(OH)F/CFP precursor. The prepared CoP3 NAs/CFP, as a 3D structured electrocatalyst with a large specific surface area and high porosity, exhibits superior bifunctional electrocatalytic activity and durability for both the HER and OER.

Self-supported three-dimensional mesoporous semimetallic WP2 nanowire arrays on carbon cloth as a flexible cathode for efficient hydrogen evolution.

The design and development of high-efficiency and non-noble metal hydrogen evolution reaction (HER) electrocatalysts with optimized nanostructures for human clean and sustainable energy systems has attracted significant research interest over the past years. Herein, self-supported semimetallic tungsten diphosphide nanowire arrays on carbon cloth (WP2 NWs/CC) were topotactically fabricated by in situ phosphidation of a WO3 NWs/CC precursor. Such a binder-free flexible HER cathode with integrated three-dimensional nanostructures can not only provide a large surface area to expose abundant active sites, but also facilitate electrolyte penetration for electrons and electrolyte ions. The WP2 NWs/CC electrode exhibits superior catalytic performance, and it needs overpotentials of 109 and 160 mV with a small Tafel slope of 56 mV dec-1 to achieve current densities of 10 and 50 mA cm-2, respectively. High stability in acidic media is also observed for the catalyst for a duration of 20 hours at least. In addition, density functional theory (DFT) calculations indicate a low kinetic energy barrier for H atom adsorption on the WP2 surface which guarantees the excellent catalytic activity of the catalyst, and the influences of phosphidation temperature on the HER activity are also studied. The excellent electrocatalytic activity makes the present 3D structured WP2 NWs/CC a promising catalyst for large scale highly pure hydrogen evolution by electrochemical water splitting.

Facile preparation of semimetallic MoP2 as a novel visible light driven photocatalyst with high photocatalytic activity

The production of clean and renewable H2 by photocatalytic water splitting has attracted much attention due to the increasing energy crisis. In this work, semimetallic MoP2 nanoparticles are discovered as a new photocatalyst to efficiently degenerate methyl orange and produce H2 from water under visible light irradiation. MoP2 nanoparticles were prepared using a solid-state reaction route via a vacuum encapsulation technique followed by acid washing. Both first-principle band-structure calculations and experimental measurements reveal typical semimetallic characteristics for MoP2. The obtained MoP2 nanoparticles display superior photocatalytic performances for the degradation of methyl orange with a good stability and the reduction of water assisted by sacrificial elemental Pt under visible light. The detection of hydroxyl radicals in the solution in the presence of MoP2 with fluorescence spectroscopy confirmed its photodegradable activities. The present study points out a new direction for developing semimetallic photocatalysts for H2 production through water splitting.

Facile preparation of semimetallic WP2 as a novel photocatalyst with high photoactivity

Searching for inexpensive and earth-abundant photocatalysts with high activities has attracted considerable research in recent years. In this work, semimetallic tungsten diphosphide (WP2) micro-particles are explored as a novel photocatalyst for the first time. The WP2 particles were synthesized through a solid-state reaction route via vacuum encapsulation technique following by water washing. The first principle calculations and electric transport measurements show a semimetallic characteristic of WP2, however a strong absorption in the UV range is observed. The prepared WP2 particles exhibit an admirable photocatalytic activity towards oxidation of methyl orange and reduction of water for H2 evolution with the assistance of co-catalyst element Pt under UV light irradiation. Hydroxyl radicals detected by fluorescence spectroscopy in the solution in the presence of WP2 under UV light irradiation confirms the photoactivity. Furthermore, the photocatalyst shows a good photostability and reusability even after three successive experiment runs. Based on the experimental measurements and theoretical calculations, a possible photocatalytic mechanism is proposed for semimetallic WP2. The present study may provide a chance for practical applications of the semimetallic material WP2 in the field of photocatalysis.