Ito Shin-Ichi, Rojas Kurt Irvin M, Yasuda Yukihiro, Noguchi Natsumi, Fukuda Kosei, Hikichi Miwa, Kang Zihao, Yuan Mei, Tsuji Ryuki, Oki Osamu, Roy Susmita, Hikita Yasuyuki, Matsuda Iwao, Miyauchi Masahiro, Hamada Ikutaro, Kondo Takahiro
Department of Materials Science, Institute of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan.
Department of Precision Engineering, Graduate School of Engineering, Osaka University, Suita, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
J Phys Chem Lett. 2024 Nov 7;15(44):10965-10976. doi: 10.1021/acs.jpclett.4c01975. Epub 2024 Oct 25.
In this study, deuterium boride (DB) nanosheets were synthesized as deuterated borophane through the ion exchange of magnesium cations in magnesium diboride with deuterons from a deuterium-type ion-exchange resin in acetonitrile. The Fourier-transform infrared absorption spectrum of DB exhibited clear isotope effects, namely the shift in the absorption peak of the B-H stretching vibrational mode to a lower wavenumber. Temperature-programmed desorption (TPD) from a mixture of DB and hydrogen boride (HB) nanosheets yielded a more intense hydrogen-deuterium (HD) signal compared to the H and D signals. This indicates that the release of hydrogen molecules from the HB nanosheets upon heating originated from interlayer hydrogen recombination rather than intralayer hydrogen recombination. TPD analysis of HB with graphene in different mixing ratios confirmed that the interlayer reaction is predominant in the lower-temperature (<623 K) regime. Meanwhile, the intralayer reaction could proceed in the higher-temperature (>623 K) regime, where hydrogen recombination occurs following H migration on the HB nanosheets.
在本研究中，通过二硼化镁中的镁阳离子与乙腈中氘型离子交换树脂的氘核进行离子交换，合成了作为氘代硼烷的硼化氘（DB）纳米片。DB的傅里叶变换红外吸收光谱表现出明显的同位素效应，即B-H伸缩振动模式的吸收峰向更低波数移动。与H和D信号相比，从DB和硼氢化氢（HB）纳米片的混合物进行程序升温脱附（TPD）产生了更强的氢-氘（HD）信号。这表明加热时HB纳米片中氢分子的释放源于层间氢重组而非层内氢重组。对不同混合比例的HB与石墨烯进行TPD分析证实，层间反应在较低温度（<623 K）范围内占主导。同时，层内反应可在较高温度（>623 K）范围内进行，此时在HB纳米片上H迁移后发生氢重组。
