Structural improvements of efficient and abundant photocatalysts and the employment of less expensive co-catalysts are appealing routes to promote the development of economically viable solar fuel production. We herein report a significant enhancement of the H₂ production from photocatalytic water splitting over K₂Ti₄O₉ after pillaring with TiO₂ pillars and loading of NiO_x as a co-catalyst. The pillaring favored the charge carrier separation within the photocatalyst framework under illumination, whereas the NiO_x co-catalyst, composed of nickel metal nanoparticles and nanostructured NiO, intensified the electron–hole separation at the surface. These are unprecedented results indicated by surface photovoltage spectroscopy, which was applied for the first time in this kind of photocatalyst composite. All modifications enhanced the H₂ evolution from 14.9 μmol, for the pristine K₂Ti₄O₉, to 982.0 μmol, for the final product, after 7 h of irradiation tests using methanol as a hole scavenger. This boost was also favored by the mesoporosity and high surface area created by the pillaring process. Moreover, NiO_x as the co-catalyst proved to be as effective as platinum and more effective than Ag and Au in this particular system.

中文翻译：

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柱撑和NiO _x助催化剂负载作为K ₂ Ti ₄ O ₉对水分解的光活性增强的替代方案†

高效和丰富的光催化剂的结构改进以及使用廉价的助催化剂是吸引人们发展经济上可行的太阳能燃料的诱人途径。我们在本文中报道了用TiO ₂柱柱撑和负载NiO _x作为助催化剂后，在K ₂ Ti ₄ O ₉上方通过光催化水分解产生的H ₂产量显着提高。支柱有利于在光照下在光催化剂框架内进行电荷载流子分离，而NiO _x由镍金属纳米颗粒和纳米结构的NiO组成的助催化剂增强了表面的电子-空穴分离。这些是表面光电压光谱法所表明的前所未有的结果，这是首次在这种光催化剂复合物中应用。在使用甲醇作为空穴清除剂进行了7小时的辐射测试后，所有修饰均使H _2的释放量从原始K ₂ Ti ₄ O _9的14.9μmol增加到最终产品的982.0μmol。提柱过程产生的介孔性和高表面积也有利于这种提振。此外，NiO _x 在这种特定的体系中，作为助催化剂的二元醇被证明与铂一样有效，并且比银和金更有效。