Abstract Photocatalysis has been rapidly developed as a sustainable technology to decompose contaminants by using photogenerated carriers excited through light irradiation. Electrons for molybdenum trioxide (MoO3) semiconductor with wide band gap can be easily transferred to its conduction band via dye sensitization effect under visible light. However, MoO3 still suffers from poor photocatalytic ability for organic dyes due to the low energy level of the conduction band and the insufficient utilization of the induced electrons. In this study, molybdenum dioxide (MoO2) nanoparticles were decorated on the surface of MoO3 nanobelts without requiring an additional Mo source by using a simple in-situ hydrothermal method. In the reaction process, the partial MoO3 itself was reduced to metallic MoO2 nanoparticles, and the resulting intimate interface between MoO2 and MoO3 could accelerate the transfer of dye sensitization-induced electrons. The as-prepared MoO2/MoO3 nanocomposites exhibited extremely enhanced visible light photocatalytic activity for decomposing rhodamine B (RhB) with the assistance of H2O2. The mechanism for high-efficiency degradation was analyzed and explored by conducting theoretical calculations and designing further experiments. The high-efficiency degradation might be due to the synergistic effect caused by the well-matched energy band structure between dyes and MoO3, and the metallic MoO2 nanoparticles, which can accelerate the production of hydroxyl radical ( OH) from H2O2. OH is a dominant reactive species for the degradation of RhB under visible light irradiation.

中文翻译：

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用 MoO2 纳米粒子装饰的 MoO3 纳米带的原位制备及其增强的光催化性能

摘要 光催化作为一种​​利用光照射激发的光生载流子分解污染物的可持续技术已得到迅速发展。具有宽带隙的三氧化钼 (MoO3) 半导体的电子可以通过可见光下的染料敏化效应轻松转移到其导带。然而，由于导带能级低和诱导电子的利用不足，MoO3对有机染料的光催化能力仍然很差。在这项研究中，二氧化钼 (MoO2) 纳米粒子通过使用简单的原位水热法装饰在 MoO3 纳米带的表面，而无需额外的 Mo 源。在反应过程中，部分 MoO3 本身被还原为金属 MoO2 纳米粒子，MoO2 和 MoO3 之间由此产生的紧密界面可以加速染料敏化诱导电子的转移。所制备的 MoO2/MoO3 纳米复合材料在 H2O2 的帮助下对分解罗丹明 B (RhB) 的可见光光催化活性表现出极大的增强。通过理论计算和进一步设计实验，对高效降解机理进行了分析和探索。高效降解可能是由于染料与 MoO3 之间良好匹配的能带结构以及金属 MoO2 纳米粒子产生的协同效应，可加速 H2O2 产生羟基自由基 (OH)。OH 是在可见光照射下降解 RhB 的主要活性物质。