Martínez-Perales Cristian, Machín Abniel, Berríos-Rolón Pedro J, Sampayo Paola, Nieves Enrique, Soto-Vázquez Loraine, Resto Edgard, Morant Carmen, Ducongé José, Cotto María C, Márquez Francisco
Nanomaterials Research Group, Department of Natural Sciences and Technology, Division of Natural Sciences and Technology, Universidad Ana G. Méndez-Gurabo Campus, Gurabo, PR 00778, USA.
Environmental Catalysis Research Lab, Division of Science, Technology and Environment, Cupey Campus, Universidad Ana G. Méndez, Cupey, PR 00926, USA.
Materials (Basel). 2025 Jun 3;18(11):2602. doi: 10.3390/ma18112602.
The widespread presence of pesticides-especially malathion-in aquatic environments presents a major obstacle to conventional remediation strategies, while the ongoing global energy crisis underscores the urgency of developing renewable energy sources such as hydrogen. In this context, photocatalytic water splitting emerges as a promising approach, though its practical application remains limited by poor charge carrier dynamics and insufficient visible-light utilization. Herein, we report the design and evaluation of a series of TiO-based ternary nanocomposites comprising commercial P25 TiO, reduced graphene oxide (rGO), and molybdenum disulfide (MoS), with MoS loadings ranging from 1% to 10% by weight. The photocatalysts were fabricated via a two-step method: hydrothermal integration of rGO into P25 followed by solution-phase self-assembly of exfoliated MoS nanosheets. The composites were systematically characterized using X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. Photocatalytic activity was assessed through two key applications: the degradation of malathion (20 mg/L) under simulated solar irradiation and hydrogen evolution from water in the presence of sacrificial agents. Quantification was performed using UV-Vis spectroscopy, gas chromatography-mass spectrometry (GC-MS), and thermal conductivity detection (GC-TCD). Results showed that the integration of rGO significantly enhanced surface area and charge mobility, while MoS served as an effective co-catalyst, promoting interfacial charge separation and acting as an active site for hydrogen evolution. Nearly complete malathion degradation (~100%) was achieved within two hours, and hydrogen production reached up to 6000 µmol g h under optimal MoS loading. Notably, photocatalytic performance declined with higher MoS content due to recombination effects. Overall, this work demonstrates the synergistic enhancement provided by rGO and MoS in a stable P25-based system and underscores the viability of such ternary nanocomposites for addressing both environmental remediation and sustainable energy conversion challenges.
农药尤其是马拉硫磷在水生环境中的广泛存在，给传统修复策略带来了重大障碍，而当前全球能源危机凸显了开发氢等可再生能源的紧迫性。在此背景下，光催化水分解作为一种有前景的方法出现了，但其实际应用仍受电荷载流子动力学不佳和可见光利用不足的限制。在此，我们报告了一系列基于TiO的三元纳米复合材料的设计与评估，该复合材料由商用P25 TiO、还原氧化石墨烯（rGO）和二硫化钼（MoS）组成，MoS的负载量按重量计在1%至10%之间。这些光催化剂通过两步法制备：首先将rGO水热整合到P25中，然后将剥离的MoS纳米片进行溶液相自组装。使用X射线衍射（XRD）、拉曼光谱、透射电子显微镜（TEM）、紫外可见漫反射光谱（DRS）和光致发光（PL）光谱对复合材料进行了系统表征。通过两个关键应用评估光催化活性：在模拟太阳辐射下对马拉硫磷（20 mg/L）的降解以及在牺牲剂存在下从水中析氢。使用紫外可见光谱、气相色谱 - 质谱联用（GC - MS）和热导检测（GC - TCD）进行定量分析。结果表明，rGO的整合显著提高了表面积和电荷迁移率，而MoS作为有效的助催化剂，促进了界面电荷分离并作为析氢的活性位点。在两小时内实现了马拉硫磷的几乎完全降解（~100%），在最佳MoS负载量下产氢量高达6000 µmol g⁻¹ h⁻¹。值得注意的是，由于复合效应，随着MoS含量的增加光催化性能下降。总体而言，这项工作证明了rGO和MoS在稳定的基于P25的体系中提供的协同增强作用，并强调了这种三元纳米复合材料在应对环境修复和可持续能源转换挑战方面的可行性。
