ANR - Development of near-infrared mediated photocatalytic nanocomposites for the treatment of turbid wastewater

由多个稠合苯环组成的多环芳烃（PAH）是碳氢化合物不完全燃烧的产物，也是加拿大广泛使用的水力压裂技术的返排产物。由于多环芳烃污染的废水对人类和野生动物具有毒性和/或致癌性，因此人们对这些废水的关注有所增加。然而，加拿大石油产量的预期增长假设了污染水的同等增长。这揭示了迫切需要注意的有效处理废水中的多环芳烃作为这些污染物在水生生态系统中的潜在的公共健康影响正在成为一个严重的问题，需要加以解决。由于紫外线的穿透深度有限，传统的基于紫外线（UV）的光催化已被证明在这些浑浊的废水介质中无效。因此，对于开发更有效、更经济的技术来降解诸如PAH的污染物存在显著需求。在这种情况下，建议将光催化过程的近红外（NIR）激活作为光催化介导的浑浊废水处理的更通用方法。拟议的项目涉及一个加拿大小组（INRS-EMT - F. Vetrone）和法国团队（皮埃尔和玛丽居里大学，表面反应实验室- G。Costentin，J. Blanchard，and S. Boujday（联合附属于NTU，新加坡，T. Steele）/巴黎南大学物理化学实验室- C。Colbeau-Justin），旨在合成新的和创新的光催化纳米复合材料，将镧系元素基上转换纳米颗粒（UCNPs）与ZnO光催化剂相结合。在此，UCNP的NIR激发时的UV发射将触发ZnO的光催化活性，导致污染物分解。这种新颖的和创新的方法将是上级到目前的方法，因为有限的紫外光的渗透将克服近红外介导的原位紫外线的产生。我们预计，这将导致一个更有效和更具成本效益的污水处理系统，并将在水务行业产生重大影响。

Polycyclic aromatic hydrocarbons (PAHs) consisting of several fused benzene rings are found as products of the incomplete combustion of hydrocarbons as well as in the flowback from hydraulic fracturing, a technique widely used in Canada. Concerns have risen about PAH-contaminated wastewaters as several studies have proven their toxicity and/or carcinogenicity to humans and wildlife. Yet, the expected increase in oil production in Canada assumes an equal increase in contaminated water. This reveals the urgent attention needed for the effective treatment of PAHs in wastewaters as the potential public health impact of these contaminants in the aquatic ecosystem is becoming a serious concern that needs to be addressed. Conventional ultraviolet (UV) light based photocatalysis has proved to be ineffectual in these turbid wastewater media due to limited penetration depth of UV light. As a consequence, there is a significant demand for the development of more efficient, cost-effective technologies to degrade pollutants such as PAHs. In this context, near-infrared (NIR) activation of the photocatalytic process is suggested as a more versatile method of photocatalysis mediated treatment of turbid wastewaters. The proposed project involves the collaborative effort between a Canadian team (INRS-EMT - F. Vetrone) and a French team (Université Pierre & Marie Curie, Laboratory of Surface Reactivity - G. Costentin, J. Blanchard, and S. Boujday (co-affiliated to NTU, Singapore, laboratory of T. Steele) / Université Paris Sud, Laboratory of Physical Chemistry - C. Colbeau-Justin) aiming for the synthesis of new and innovative photocatalytic nanocomposites combining lanthanide-based upconverting nanoparticles (UCNPs) with a ZnO photocatalyst. Herein, the UV emission upon NIR excitation of the UCNPs will trigger the photocatalytic activity of the ZnO resulting in pollutant breakdown. This novel and innovative approach will be superior to current methodologies, as the limited penetration of UV light will be overcome by NIR-mediated in-situ UV generation. We expect that it will lead to a more efficient and cost-effective system for wastewater treatment and will create significant impact in the water industry.