Lin Yu-Rou, Zheng Meng-Wei, Liu Shou-Heng
Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
Chemosphere. 2023 Nov;341:140118. doi: 10.1016/j.chemosphere.2023.140118. Epub 2023 Sep 9.
To maintain a comfortable and healthy indoor environment without large amounts of energy consumption is of great importance. The progress of multifunctional indoor coatings with formaldehyde photodegradation and humidity buffering capability is necessary. From the viewpoints of circular economy, the preparation of effective photocatalysts (denoted as sFCC/GCN-x and ESF/GCN-y) via the decoration of recycling industrial wastes (i.e., spent fluid catalytic cracking catalysts (sFCC) and enhancement silica fume (ESF)) onto graphitic carbon nitride (GCN) by using a simple route is reported. The obtained results show that the prepared sFCC/GCN-0.15 and ESF/GCN-0.15 photocatalysts have the rate constants of formaldehyde degradation of 0.0075 and 0.0082 min, respectively, which are superior to that of pristine GCN (0.0044 min) under visible-light irradiation. The enhanced transfer kinetics of photogenerated electrons and declined recombination of electron-hole pairs may account for the surpassing photocatalytic performance. Results obtained from electron paramagnetic resonance spectra and Mott-Schottky plots indicate that the formation of ･O via the reaction of O with electrons generated on the conduction band is the major reaction pathway to photodegrade formaldehyde under visible light. To further assess the real applications of prepared photocatalysts, the sFCC/GCN-0.15 and ESF/GCN-0.15 are used to fabricate the multifunctional coatings (denoted as s- and E-coatings) with sFCC and ESF as the main compositions. Experimentally, the E-coatings could reach the formaldehyde degradation efficiency of ca. 84.5% after 3 h of visible light irradiation and excellent humidity buffering ability (293.8 g m) which is at least 10-folds higher than commercial coatings (28.9 g m). This notable progress of humidity buffering capacity on E-coatings can be attributed to their surface textural properties. Most importantly, this study exemplifies the valorization of inorganic silica wastes to produce sustainable and multifunctional coatings which may offer the practical and cost-effective applications in the indoor living space.
在不消耗大量能源的情况下维持舒适健康的室内环境至关重要。具有甲醛光降解和湿度缓冲能力的多功能室内涂料的研发很有必要。从循环经济的角度出发，本文报道了通过简单方法将回收工业废料（即废流化催化裂化催化剂（sFCC）和增强硅灰（ESF））负载到石墨相氮化碳（GCN）上制备有效光催化剂（分别记为sFCC/GCN-x和ESF/GCN-y）的过程。结果表明，制备的sFCC/GCN-0.15和ESF/GCN-0.15光催化剂在可见光照射下甲醛降解速率常数分别为0.0075和0.0082 min⁻¹，优于原始GCN（0.0044 min⁻¹）。光生电子转移动力学增强以及电子 - 空穴对复合减少可能是其光催化性能优异的原因。电子顺磁共振光谱和莫特 - 肖特基曲线结果表明，O₂与导带上产生的电子反应形成･O₂⁻是可见光下光降解甲醛的主要反应途径。为进一步评估制备的光催化剂的实际应用，以sFCC/GCN-0.15和ESF/GCN-0.15为主要成分制备了多功能涂料（分别记为s-涂层和E-涂层）。实验表明，E-涂层在可见光照射3小时后甲醛降解效率可达约84.5%，且具有优异的湿度缓冲能力（293.8 g m⁻²），比商业涂料（28.9 g m⁻²）至少高10倍。E-涂层湿度缓冲能力的显著提升可归因于其表面结构性质。最重要的是，本研究例证了无机硅废料的价值化利用，以生产可持续的多功能涂料，这可能在室内生活空间提供实用且经济高效的应用。
