Tungsten Oxide Nanowire Catalyst

Due to the continuous consumption of fossil fuels and the increasingly prominent environmental problems, the search for clean and sustainable use of new energy has become an increasingly important topic. Among many new energy sources, hydrogen energy has become a research hotspot due to its high energy density, clean (water products) and sustainable utilization.

Hydrogen production by electrocatalytic decomposition of water is a highly efficient and practical method. At present, platinum-based catalysts are the most active catalysts for hydrogen evolution reaction, but their high cost and low content greatly limit the large-scale application.

So far, how to effectively utilize transition metal oxides, that is, how to load them on highly conductive carriers, especially how to prepare irregular structures that can provide larger specific surface area and more active sites, is still a big challenge. For example, some researchers have prepared tungsten oxide nanowire catalysts to enhance the catalytic activity of hydrogen evolution reaction by increasing the oxygen vacancy content and increasing the specific surface area of the materials. The synthesis process of the tungsten oxide nanowire catalysts includes:
Ammonium tetrathiotungstate was used as tungsten source, dopamine as carbon source and polymerizer, and a two-step reaction method was adopted.

Step one:
Ammonium tetrathiotungstate was dissolved in a mixture of deionized water and ethanol, and the pH value of the solution was adjusted to about 8 by ammonia. Then a certain concentration of dopamine hydrochloride solution was added to the above solution drop by drop, and the solution was stirred at room temperature. After a certain time of reaction, the precipitation was separated by centrifugation, and the yellow powder was tungsten-polydopamine precursor.

Step two:
The above yellow powder is treated at high temperature in a tubular furnace at 750 ℃, nitrogen atmosphere, heating time of 3 hours and heating rate of 2 min - 1. At this time, a black powder, tungsten oxide nanowire catalyst with high hydrogen evolution activity, was obtained.

It was found that the synthesis efficiency of nanowires was high, and tungsten oxide nanowires with super-long size were generated after heating in polymer inert gas. The catalyst had high hydrogen evolution activity and high stability in acidic conditions.

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