Interfacial coupled engineering of plasmonic amorphous MoO_3-x nanodots/g-C₃N₄ nanosheets for photocatalytic water splitting and photothermal conversion

Semiconductor-based plasmonic materials have attracted extensive attention for photocatalytic systems. However, their photocatalytic reactions are hindered by limited light-harvesting ability and the transfer rate of photo-generated electrons. Herein, vacancy engineering and phase engineering are rationally integrated to develop amorphous molybdenum oxide (a-MoO_3−x) nanodots anchored on g-C₃N₄ as a highly active photocatalyst. Through high localized surface plasmon resonance (LSPR) effect of a-MoO_3−x nanodots and tunable electrical properties induced by the heterostructural interface, the Z-scheme a-MoO_3−x/g-C₃N₄ heterostructure demonstrates broadband absorption and the excited photo-generated electrons. Further theoretical calculations demonstrate that the enhancement of photocatalytic and photothermal performance is mainly attributed to the highly localized Anderson tail states of a-MoO_3−x. Consequently, the a-MoO_3−x/g-C₃N₄ heterostructure exhibits a photocurrent density of ∼36.5 μA cm⁻², which is about 2.7 and 4.1 times higher than that of pure g-C₃N₄ nanosheets (∼13.5 μA cm⁻²) and a-MoO_3−x nanodots (∼9 μA cm⁻²), respectively. The photocatalytic performance enhancement relying on defects and long-range disorder of a-MoO_3−x in Z-scheme heterostructure is explored.