Two‐dimensional (2D) semiconducting boron nanosheets (few‐layer borophene) have been theoretically predicted, but their band gap tunability has not been experimentally confirmed. In this study, hydroxy‐functionalized borophene (borophene‐OH) with tunable band gap was fabricated by liquid‐phase exfoliation using 2‐butanol solvent. Surface‐energy matching between boron and 2‐butanol produced smooth borophene, and the exposed unsaturated B sites generated by B−B bond breaking during exfoliation coordinated with OH groups to form semiconducting borophene‐OH, enabling a tunable band gap of 0.65–2.10 eV by varying its thickness. Photoelectrochemical (PEC) measurements demonstrated that the use of borophene‐OH to fabricate working electrodes for PEC‐type photodetectors significantly enhanced the photocurrent density (5.0 μA cm⁻²) and photoresponsivity (58.5 μA W⁻¹) compared with other 2D monoelemental materials. Thus, borophene‐OH is a promising semiconductor with great optoelectronic potential.

中文翻译：

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羟基官能化硼砂的带隙工程技术，具有优异的光电性能。

二维（2D）半导体硼纳米片（几层硼苯）已得到理论预测，但其带隙可调性尚未得到实验证实。在本研究中，使用2-丁醇溶剂通过液相剥离法制备了具有可调带隙的羟基官能化硼苯（borophene-OH）。硼和2-丁醇之间的表面能匹配产生光滑的borophene，剥落过程中由BB键断裂产生的裸露不饱和B位点与OH基团配合形成半导电的borophene-OH，可调节的带隙为0.65–2.10 eV。通过改变其厚度。光电化学（PEC）测量表明，使用borophene-OH来制造PEC型光电探测器的工作电极可显着提高光电流密度（5.0μAcm ^-2）和光敏性（58.5μAW ^-1）与其他2D单元素材料相比。因此，borophene-OH是具有巨大光电潜力的有前途的半导体。