Muangnapoh Tanyakorn, Srimara Piyarach, Vas-Umnuay Paravee
National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency, 111 Thailand Science Park, Klong Luang, Pathumthani 12120, Thailand.
Center of Excellence in Particle and Material Processing Technology, Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand.
ACS Omega. 2020 Sep 14;5(38):24584-24591. doi: 10.1021/acsomega.0c03077. eCollection 2020 Sep 29.
Cermet-based solar absorbers containing nickel (Ni) in a nanochain (NC) structure embedded in an aluminum oxide (AlO) film demonstrated a high absorptance of more than 90% of the solar spectrum. In this work, Ni NCs were successfully prepared by a simple chemical reduction method without the assistance of a template or magnetic field. The formation of Ni nanoparticles (NPs) in different configurations was controlled by adjusting the NaOH:NiCl molar ratio. Not only was NaOH used to adjust the solution pH but it also induced the reduction reaction to be faster and so resulted in a larger number of Ni nuclei. Together with the intrinsic magnetic property of Ni, Ni NPs tended to orient in a chain-like manner to form Ni NCs that remained stable throughout the reaction. Increasing the NaOH:NiCl molar ratio up to 8 led to a uniform morphology of Ni NCs. However, at higher molar ratios (above 8), the NCs were likely to collapse at the end of the reaction, forming near-globular particles. With its unique structure, metallic Ni NCs were employed by incorporating them into a ceramic layer of AlO, which can be used as efficient cermet materials. Compared to a conventional cermet with embedded spherical Ni NPs, a 16.4% increase in solar absorptance was observed with the Ni NCs due to their enhanced absorption and scattering in the solar spectrum. Moreover, increasing the Ni NC content in the AlO layer gradually enhanced the solar absorptance to 0.91 and so was a good solar absorber.
基于金属陶瓷的太阳能吸收器，其中镍（Ni）以纳米链（NC）结构嵌入氧化铝（AlO）薄膜中，对太阳光谱的吸收率超过90%。在这项工作中，通过一种简单的化学还原方法成功制备了Ni NCs，无需模板或磁场的辅助。通过调整NaOH:NiCl摩尔比来控制不同构型的Ni纳米颗粒（NPs）的形成。NaOH不仅用于调节溶液pH值，还能使还原反应更快，从而产生更多的Ni核。结合Ni的固有磁性，Ni NPs倾向于以链状方式排列形成Ni NCs，在整个反应过程中保持稳定。将NaOH:NiCl摩尔比提高到8会导致Ni NCs形态均匀。然而，在更高的摩尔比（高于8）下，NCs在反应结束时可能会坍塌，形成近球形颗粒。凭借其独特的结构，金属Ni NCs通过将其掺入AlO陶瓷层中得以应用，该陶瓷层可用作高效的金属陶瓷材料。与嵌入球形Ni NPs的传统金属陶瓷相比，由于Ni NCs在太阳光谱中的吸收和散射增强，其太阳吸收率提高了16.4%。此外，增加AlO层中Ni NC的含量会逐渐将太阳吸收率提高到0.91，因此是一种良好的太阳能吸收器。
