Composites of W₁₈O₄₉ Nanowires with g‑C₃N₄/RGO Nanosheets for Broadband Light-Driven Photocatalytic Wastewater Purification

Developing a photocatalyst that can effectively utilize the full solar spectrum remains a high-priority objective in the ongoing pursuit of efficient light-to-chemical energy conversion. Herein, the ternary nanocomposite g-C₃N₄/RGO/W₁₈O₄₉ (CN/RGO/WO) was constructed and characterized by a variety of techniques. Remarkably, under the excitation of photon energies ranging from the ultraviolet (UV) to the near-infrared (NIR) region, the photocatalytic performance of the CN/RGO/WO nanocomposite exhibited a significant enhancement compared with single component g-C₃N₄ or W₁₈O₄₉ nanosheets for the degradation of methyl orange (MO). The MO photodegradation rate of the optimal CN/1.0 wt% RGO/45.0 wt% WO catalyst reached 0.816 and 0.027 min^–1 under UV and visible light excitation, respectively. Even under low-energy NIR light, which is not sufficient to excite g-C₃N₄, the MO degradation rate can still reach 0.0367 h^–1, exhibiting a significant enhancement than pure W₁₈O₄₉. The outstanding MO removal rate and stability were demonstrated by CN/RGO/WO nanocomposites, which arise from the synergistic effect of localized surface plasmon resonance effect induced by W₁₈O₄₉ under vis–NIR excitation and the Z-scheme nanoheterojunction of W₁₈O₄₉ and g-C₃N₄. In this work, we have exploited the great potential of integrating nonmetallic plasmonic nanomaterials and good conductor RGO to construct high-performance g-C₃N₄-based full-solar spectral broadband photocatalysts.