Photoelectrochemical (PEC) water splitting has been a promising approach for solar energy conversion to meet the clean energy demand. Design and fabrication of high-quality photoelectrode for water splitting with enhanced light absorption, as well as efficient charge separation and transport are challenging. Herein, two-dimensional (2D) WO_3-x nanosheets with unique fullerene shell-like nanostructure are prepared with assistance of supercritical CO₂ (SC CO₂). Then a novel plasmonic photoanode heterostructure composed of plasmonic Ag and fullerene shell-WO_3-x is synthesized for PEC water splitting and photooxidation degradation. The unique co-existence of amorphous and crystalline structure of WO_3-x leads to uniformly distribution of Ag nanoparticles, simultaneously increasing the active site density and improving the electron transport. Femtosecond time-resolved IR absorption spectrum analysis indicates the surface plasmonic resonance (SPR) effect of Ag nanoparticles can mediate efficient electron transfer to fullerene shell-WO_3-x nanosheets. The photoresponse of the plasmonic Ag/fullerene shell-WO_3-x heterostructure is 2.5 times higher than that of fullerene shell-WO_3-x. By combining the synergistic effects of the special microstructures of plasmonic Ag and fullerene shell-WO_3-x, we are able to design a low-cost photoelectronic catalyst for efficient PEC water splitting and photooxidation degradation. The strategy developed here provides a fascinating way to synthesize high efficient photoelectronic catalysts for solar energy conversion.

光电化学（PEC）的水分解法已经成为一种有前途的太阳能转化方法，可以满足清洁能源的需求。设计和制造用于光分解的高质量光电极，具有增强的光吸收能力以及有效的电荷分离和传输能力，具有挑战性。在此，借助于超临界CO ₂（SC CO ₂）制备具有独特的富勒烯壳状纳米结构的二维（2D）WO _3-x纳米片。然后合成了由等离激元Ag和富勒烯壳WO _3-x组成的新型等离激元光阳极异质结构，用于PEC水分解和光氧化降解。WO _3-x的无定形和晶体结构的独特共存导致Ag纳米粒子的均匀分布，同时增加了活性位点密度并改善了电子传输。飞秒时间分辨的红外吸收光谱分析表明，Ag纳米粒子的表面等离子体共振（SPR）效应可以介导有效的电子转移至富勒烯壳WO _3-x纳米片。等离激元的Ag /富勒烯壳WO的光响应_3-x异质结构比富勒烯壳WO的高2.5倍_3-x 。通过结合等离激元Ag和富勒烯壳的特殊微观结构的协同效应-WO _3-x，我们能够设计出一种低成本的光电催化剂，以实现有效的PEC水分解和光氧化降解。此处开发的策略提供了一种迷人的方式来合成用于太阳能转化的高效光电催化剂。