College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China.
School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China.
Sci Total Environ. 2021 Sep 15;787:147536. doi: 10.1016/j.scitotenv.2021.147536. Epub 2021 May 5.
The applications of photocatalytic pollutant degradation have remained limited due to the low efficiency of solar energy utilization. In this study, a photothermal catalyst consisting of reduced graphene oxide @ black TiO (RGO@BT) nanofluid with effective full-spectrum (from ultraviolet to infrared light) absorption was synthesized by a typical two-step method of high temperature calcination and hydrothermal method. Moreover, the photothermal catalytic performance of the RGO@BT nanofluid on tetracycline was verified. Compared with individual processes (i.e, photocatalysis and thermocatalysis), the photothermal catalytic process significantly enhanced tetracycline degradation under simulated global standard spectrum sunlight (AM 1.5G, 1000 W m). The maximum photothermal conversion efficiency reached 91.8%, which resulted in 94.7% tetracycline degradation (40 mg L) after 120 min of treatment with 200 mg L RGO@BT nanofluid. Holes, OH, and O were found to be the main active species during the photothermal catalytic process. Moreover, heat was spontaneously converted from light energy without the use of any external energy source. The elevated system temperature facilitated the tetracycline degradation based on the Arrhenius behavior. These findings provide insights into the improvement of photocatalytic efficiency in organic contaminant degradation via solar energy-efficient photothermal conversion materials.
由于太阳能利用效率低，光催化污染物降解的应用仍然受到限制。在这项研究中，通过典型的高温煅烧和水热法两步法合成了具有有效全光谱（从紫外光到红外光）吸收能力的还原氧化石墨烯@黑 TiO（RGO@BT）纳米流体光热催化剂。此外，还验证了 RGO@BT 纳米流体对四环素的光热催化性能。与单一过程（即光催化和热催化）相比，在模拟全球标准光谱阳光（AM 1.5G，1000 W m）下，光热催化过程显著提高了四环素的降解。在 120 分钟内，用 200mg/L 的 RGO@BT 纳米流体处理后，最大光热转换效率达到 91.8%，四环素的降解率达到 94.7%（40mg/L）。在光热催化过程中发现空穴、OH 和 O 是主要的活性物质。此外，热量是自发地从光能转化而来的，而无需使用任何外部能源。升高的系统温度有利于基于阿仑尼乌斯行为的四环素降解。这些发现为通过太阳能高效光热转换材料提高有机污染物降解的光催化效率提供了思路。
