Free of posttransfer, on-surface synthesis (OSS) of single-atomic-layer nanostructures directly on semiconductors holds considerable potential for next-generation devices. However, due to the high diffusion barrier and abundant defects on semiconductor surfaces, extended and well-defined OSS on semiconductors has major difficulty. Furthermore, given semiconductors’ limited thermal catalytic activity, initiating high-barrier reactions remains a significant challenge. Herein, using TiO 2 (011) as a prototype, we present an effective strategy for steering the molecule adsorption and reaction processes on semiconductors, delivering lengthy graphene nanoribbons with extendable widths. By introducing interstitial titanium (Ti int ) and oxygen vacancies (O v ), we convert TiO 2 (011) from a passive supporting template into a metal-like catalytic platform. This regulation shifts electron density and surface dipoles, resulting in tunable catalytic activity together with varied molecule adsorption and diffusion. Cyclodehydrogenation, which is inefficient on pristine TiO 2 (011), is markedly improved on Ti int /O v -doped TiO 2 . Even interribbon cyclodehydrogenation is achieved. The final product’s dimensions, quality, and coverage are all controllable. Ti int doping outperforms O v in producing regular and prolonged products, whereas excessive Ti int compromises molecule landing and coupling. This work demonstrates the crucial role of semiconductor substrates in OSS and advances OSS on semiconductors from an empirical trial-and-error methodology to a systematic and controllable paradigm.

中文翻译：

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从半导体实现表面合成的类金属催化


无需后转移，直接在半导体上进行单原子层纳米结构的表面合成（OSS）对于下一代器件具有巨大的潜力。然而，由于半导体表面的高扩散势垒和丰富的缺陷，在半导体上扩展和定义良好的OSS具有很大的困难。此外，鉴于半导体的热催化活性有限，引发高势垒反应仍然是一个重大挑战。在此，使用TiO 2 (011)作为原型，我们提出了一种有效的策略来控制半导体上的分子吸附和反应过程，从而提供具有可延伸宽度的长石墨烯纳米带。通过引入间隙钛（Ti int ）和氧空位（O v ），我们将TiO 2 (011)从被动支撑模板转化为类金属催化平台。这种调节改变了电子密度和表面偶极子，从而产生可调节的催化活性以及不同的分子吸附和扩散。环脱氢在原始TiO 2 (011)上效率较低，但在Ti int /O v 掺杂的TiO 2 上得到显着改善。甚至实现了带间环化脱氢。最终产品的尺寸、质量、覆盖率都是可控的。 Ti int 掺杂在产生规则和延长产物方面优于 O v，而过量的 Ti int 会损害分子着陆和耦合。这项工作证明了半导体衬底在 OSS 中的关键作用，并将半导体 OSS 从经验性的试错方法推进到系统可控的范式。