Gr-C3N is the latest 'wonder material' - another 'graphene' in the making. Currently it is very expensive, but it costs very little - and requires only modest skills and equipment to make your own. The cost of the raw material, Urea, is trivial and it is readily available.
Current costs to buy it 'ready made' and of guaranteed quality are extortionate - on this website it is £135.00 (US$180) for 200 milligrams - that's $900/gm.
So what does it do? Here are just some of it's features. It is harder than diamond, can adsorb up to 10X it's mass of hydrogen, is a photo-catalyst and an efficient electron emitter. it can also be used as a replacement for Lithium in CN/Na batteries and much more. I cannot help but wonder if this would be a useful hydrogen carrier for LENR?
The video below, by Robert Murray-Smith (no relation, but no fool either) describes the synthesis and post-treatment of GrCN from Urea. !0 minutes well spent for anybody that likes to play the chemist. I cannot guarantee the efficiency or the purity of the end product- but I have checked out his sources and they are good.
EtA- info on simple synthesis and properties:-