A compound that is used for lubrication has found a new application, err, actually at least two – as a supercapacitor and hydrogen catalyst. Chemists at the Rice University, led by James Tour, took molybdenum disulphide and turned it into a thin, nanoporous film.
While it was nonreactive on its flat sides, it was found that its edges are a very good catalyst to separate hydrogen from water. Tour and his team tried to create films of the material that maximize the number of exposed edges that would not only make it easier to “make” hydrogen but may also be used in batteries, among other things.
The material looks like graphene, the wonder material made of carbon atoms arranged in a single sheet, when viewed from the “top”. On the side, however, the material looks like a sandwich of sulphur “bread” with molybdenum spread in between, in contrast to graphene’s single layer. Because of this, the material has more edges. The more the edges, the greater its potential for either hydrogen synthesis or energy storage.
So how does a sheet of sulphur and molybdenum atoms gets its edge, or rather edges? Tour says that their material is full of holes, which in this case is a very good thing. Hence, the molybdenum disulphide they made with their process yields short planes of the material, hence a lot of edges, “as though the material had bore holes drilled all the way through,” added Tour.
They tried the material as a catalyst to separate hydrogen from water. “Its performance as a HER (hydrogen evolution reaction) generator is as good as any molybdenum disulfide structure that has ever been seen, and it’s really easy to make,” Tour said. Because of this, it’ll find much application if fuel cell technology takes off.
On the other hand, the material also has much use in energy storage. The team tried making supercapacitors with the material. Based on their tests, the capacity of the supercapacitor was still at 90% after 10,000 charge-discharge cycles and 83% after 20,000.
The team hasn’t gotten far as making batteries using the material. However, with the publication of the methodology in the journal Advanced Materials, another research team may pick it up and put it in a battery soon.
With all the possibilities that I guess that Rice University’s molybdenum disulphide opens up, we can say that the material is at the cutting edge of alternative energy.
