在現代，科技與工業技術的進步造成人們對能源的需求顯著的提升。由於傳統燃燒生質燃料產生的汙染問題以及其可預見之耗盡皆促使各種新興的可再生能源獲取方式的開發。其中，藍色能源，亦即由海洋中產出的能源引發了國際間化學與材料領域科學家們的關注。而因為廣泛存在於世界上之海水/淡水交界以及對環境友善的特性，能將鹽濃度差透過離子選擇膜轉換為電能而不會造成汙染的滲透能源轉換在近年來受到了越來越多的關注。在下一個世代的滲透能源轉換中，結構有序且具高離子選擇性與離子二極體行為之離子選擇膜因為上述之性質可將系統內之離子電流放大，儼然成為了提高效能的關鍵。科學家們以上述之性質為依據，已開發了多種不同的異質離子二極體薄膜應用於滲透能源轉換，然而目前文獻中以回報之最大轉換功率密度仍無法達到可應用於商業運轉的基準(5 W/m2)。與以前的研究主要關注於離子選擇層不同，本研究將關注點轉移到了異質膜的支撐層上。受細胞膜中生物離子通道的啟發，我們開發了一種基於氧化鋁離子-納米通道薄膜(INM)的新型支撐層。通過大量的參數研究(例如，離子通道長度，鹽度梯度和納米通道幾何形狀的影響)，我們發現經優化後單純的離子奈米通道支撐層在合成海水與淡水之鹽度差中可提取較大多數最先進的離子二極體薄膜為高之3.67 W/m2的功率密度。我們相信，離子-奈米通道薄膜支撐層的開發將對滲透能源轉換達到商業化基準的進程中有巨大的潛力。

The advance in modern technologies and industries have significantly increased the demand of energy. Due to the limited fossil fuel and serious pollution problems caused by the traditional burning of biomass fuels and their predictable depletion, various of renewable energy sources have been developed. Among them, blue energy, power generated from sea water, has attracted explosive interests from international communities ranging from chemical to material sciences. Osmotic power conversion, in which a salinity gradient across an ion selective membrane can be converted into electricity without involving chemical pollutants, is one type of blue energies and recently receives growing attention because of its environmentally friendly characteristics and the widely existence of sea water/fresh water junctions in the world. Towards next-generation high-performance osmotic power, it has been shown that the keys are to exploit the membranes with ordered structure, highly ion selectivity, and ionic diode behavior that is able to amplify ionic current of the system. To attain this goal, there have been several attempts in developing various kinds of heterogeneous ionic diode membranes for osmotic power conversion. However, the maximum power densities reported in the literatures are still below the commercial benchmark (5 W/m2). Different from previous studies focusing primarily on the ion selective layer, this study turns the focus into the supporting substrate layer of the heterogeneous membrane. Inspired by biological ion channels in the cell membrane, we develop a new type of substrate layer based on the alumina ion-nanochannels membrane (INM). Through a large number of parametric studies (e.g., the influences of ion-channel length, salinity gradients and nanochannel geometry), it is found that the bare INM can achieve a power density as high as 3.67 W/m2 by mixing synthetic seawater and river water, higher than most of the state-of-the-art ionic-diode-membrane-based osmotic power generators. It is believed that the INM developed is of high potential in promoting the osmotic power across the commercialization benchmark.

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