Abstract Surface engineering of one-dimensional (1D) TiO2-based heterostructures is extremely vital to the development of new photocatalysts with superior performances. Herein, the Al2O3 heterojunctions onto TiO2 nanofibers were facilely fabricated by a surfactant-free approach, via employing graphene oxide (GO) sheets as a reliable catalyst of regulating the growth kinetics of heterojunctions. Through adjusting the GO content, the oxygen-containing functional groups of GO provided nucleation sites of Al2O3 species while restricting their growth in the limited space. As a result, the morphology of Al2O3 heterojunctions evolved from nanoflakes to nanospikes outside the TiO2 nanofibers that served as robust skeletons. Owing to the distinctive morphology and the effective electron transfer pathway, the photocurrent density of the spiny RGO/Al2O3/TiO2 nanofibers was 3.5-times higher than that of pure Al2O3/TiO2 nanofibers counterparts toward photoelectrochemical reaction under visible-light irradiation. The present work highlights the pivotal role of graphene sheets in controlling the hierarchical growth of TiO2-based heterostructures with tunable morphology and compositions.

中文翻译：

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通过无表面活性剂的方法，基于石墨烯对 TiO2 纳米纤维外 Al2O3 异质结分层生长的调制

摘要 一维 (1D) TiO2 基异质结构的表面工程对于开发具有优异性能的新型光催化剂至关重要。在此，通过使用氧化石墨烯 (GO) 片材作为调节异质结生长动力学的可靠催化剂，通过无表面活性剂的方法轻松制造了在 TiO2 纳米纤维上的 Al2O3 异质结。通过调节GO含量，GO的含氧官能团提供了Al2O3物种的成核位点，同时限制了它们在有限空间内的生长。结果，Al2O3 异质结的形态从纳米薄片演变为作为坚固骨架的 TiO2 纳米纤维外部的纳米尖峰。由于独特的形态和有效的电子转移途径，在可见光照射下，多刺 RGO/Al2O3/TiO2 纳米纤维的光电流密度是纯 Al2O3/TiO2 纳米纤维对应物的 3.5 倍，用于光电化学反应。目前的工作强调了石墨烯片在控制具有可调形态和组成的 TiO2 基异质结构的分级生长方面的关键作用。