Abstract：
Nanofluidic energy harvesting from salinity gradients is studied in 2D nanomaterials-based membranes with promising performance as high ion selectivity and fast ion transport. In addition, moving forward to scalable, feasible systems requires environmentally friendly materials to make the application sustainable. Clay-based membranes are attractive for being environmentally friendly, non-hazardous, and easy to manipulate materials. However, achieving underwater stability for clay-based membranes remains challenging. In this work, the synthetic clay Laponite is used to prepare clay-based membranes with high stability and excellent performance for osmotic energy harvesting. The Laponite membranes (Lap-membranes) are stabilized by low-temperature annealing treatment to effectively reduce the interlayer space, achieving a continuous operation under salinity gradients. Furthermore, the Lap-membranes conserve integrity while soaking in water for more than one month. The output power density improves from ≈4.97 W m-2 on the pristine membrane to ≈9.89 W m-2 in the membrane treated 12 h at 300 °C from a 30-fold concentration gradient. Especially, It is found that the presence of interlayer water to be favorable for ion transport. Different mechanisms are proposed in the Lap-membranes involved for efficient ion selectivity and the states found with varying annealing temperatures. This work demonstrates the potential application of Laponite based nanomaterials for nanofluidic energy harvesting.
摘要：
在基于二维纳米材料的膜中研究了从盐度梯度中收集纳米流体能量，具有高离子选择性和快速离子传输等有希望的性能。此外,朝着可扩展的方向前进，可行的系统需要环保材料，以使应用可持续。粘土基膜具有环保的吸引力，无危险,和易于操作的材料。然而,实现基于粘土的膜的水下稳定性仍然具有挑战性。在这项工作中,合成粘土Laponite用于制备具有高稳定性和优异的渗透能量收集性能的粘土基膜。通过低温退火处理使Laponite膜（Lap-filmes）稳定，以有效减少层间空间，在盐度梯度下实现连续运行。此外，在水中浸泡一个月以上时，膜可以保持完整性。输出功率密度从原始膜上的约4.97Wm-2提高到在300°C下处理12小时的膜中的约9.89Wm-2，浓度梯度为30倍。尤其是,发现层间水的存在有利于离子传输。在涉及有效离子选择性的Lap膜中提出了不同的机制，以及随着退火温度的变化而发现的状态。这项工作证明了基于Laponite的纳米材料在纳米流体能量收集中的潜在应用。
