Nitrogen adsorption via charge transfer on vacancies created during surfactant assisted exfoliation of TiB2

Titanium diboride (TiB<inf>2</inf>), a layered ceramic material, comprised of titanium atoms sandwiched in between honeycomb planes of boron atoms, exhibits a promising structure to utilize the rich chemistry offered by the synergy of titanium and boron. TiB<inf>2</inf> has been primarily investigated and applied in its bulk form. This perspective is, however, fast evolving with a number of efforts aimed at exfoliating TiB<inf>2</inf>. Here, we show that it is possible to delaminate TiB<inf>2</inf> into ultrathin, minimally functionalized nanosheets with the aid of surfactants. These nanosheets exhibit crystalline nature and their chemical analysis reveals vacant sites within the nanosheets. These vacancies facilitate the chemisorption of N<inf>2</inf> onto the TiB<inf>2</inf> nanosheets under ambient conditions without the aid of any energy, this finding was unexpected. This remarkable activity of TiB<inf>2</inf> nanosheets is attributed to vacancies and the Ti-B synergy, which enhance the adsorption and activation of N<inf>2</inf>. We obtained supplemental insights into the N<inf>2</inf> adsorption by Density Functional Theory (DFT) studies, which reveal how charge transfer among Ti, B, and N<inf>2</inf> results in N<inf>2</inf> adsorption. The DFT studies also show that nanosheets having more vacancies result in increased adsorption when compared with nanosheets having less vacancies and bulk TiB<inf>2</inf>