Dual-defected pine-needle W18O49–TiO2(R)–TiO2(A) heterojunctions for the complete elimination of naphthalene

Abstract

A dual-defected pine-needle W₁₈O₄₉–TiO₂(A)–TiO₂(R) heterojunction photocatalyst was designed and successfully constructed for the first time through facile hydrothermal and solvothermal methods, and its photocatalytic activity for naphthalene elimination under visible light was investigated. An increase in the content of rutile TiO₂ resulted in dual defect formation together with Ti³⁺ and oxygen vacancy generation was obtained when sea urchin-like W₁₈O₄₉ nanospines were epitaxially grown on the surface of TNWs sample. Compared to the naphthalene degradation ratio of TNWs (37.3%) and W₁₈O₄₉ (53.1%), the WTNWs-2 sample with the best light scattering effect and a longer average lifetime τ_ave of 7.59 ns can offer complete naphthalene degradation owing to the synergistic effects between ternary heterojunction and defect engineering. Combined with the LSPR effect of W₁₈O₄₉, a dual S-scheme mechanism was followed when ˙O₂⁻ and h⁺ were the main active substances. Through this study, an effective strategy is provided to eliminate the impact of naphthalene on the environment.