Vertically aligned metal halide perovskite (MHP) nanowires are promising for various optoelectronic applications, which can be further enhanced by heterostructures. However, present methods to obtain free-standing vertically aligned MHP nanowire arrays and heterostructures lack the scalability needed for applications. We use a low-temperature solution process to prepare free-standing vertically aligned green-emitting CsPbBr₃ nanowires from anodized aluminum oxide templates. The length is controlled from 1 to 20 μm by the precursor amount. The nanowires are single-crystalline and exhibit excellent photoluminescence, clear light guiding and high photoconductivity with a responsivity of 1.9 A/W. We demonstrate blue-green heterostructured nanowire arrays by converting the free-standing part of the nanowires to CsPbCl_1.1Br_1.9 in an anion exchange process. Our results demonstrate a scalable, self-aligned, and lithography-free approach to achieve high quality free-standing MHP nanowires arrays and heterostructures, offering new possibilities for optoelectronic applications.

Water evaporation–induced electricity generators (WEGs) are regarded as one of the most promising solutions for addressing the increasingly severe environmental pollution and energy crisis. Owing to the potential carbon emission in the preparation process of WEGs, whether WEG represents a clean electricity generation technology is open to question. Here, a brand‐new strategy is proposed for manufacturing negative carbon emission WEG (CWEG). In this strategy, the microalgae film is used as the electricity generation interface of WEG, which achieves a stable open‐circuit voltage (V_oc) of 0.25 V and a short‐circuit current (I_sc) of 3.3 µA. Since microalgae can capture carbon dioxide during its growing process, CWEG holds great promise to generate electricity without carbon emissions in the full life cycle compared with other WEGs. To the best of the author's knowledge, this is the first work using microalgae films to fabricate WEG. Therefore, it is believed that this work not only provides a new direction for designing high‐efficiency and eco‐friendly WEG but also offers an innovative approach to the resource utilization of microalgae.

L‐Aspartic acid (L‐Asp) poses a dual function, which can affect the evaporation and crystallization process of the high‐salinity brine by altering the physical or chemical properties of the salts. MSWI (municipal solid waste incineration) fly ash washing leachate, as a typical high‐salinity brine, is utilized here to validate this hypothesis under the simulation guidance. Since L‐Asp has stronger adsorption energy on the (110) crystal face of CaCO₃, L‐Asp can facilitate the preferential growth of more valuable vaterite during the softening process (pretreatment before crystallization). Subsequently, the resulting solution undergoes a stable interfacial solar‐driven crystallization process under the L‐Asp, with a high salt recovery ratio of 0.14 kg m⁻² h⁻¹ within 40 h under 1 sun. Finally, to harness the “cradle to grave” full life cycle utilization of washing leachate, the extracted mixed salts are utilized for moisture‐enabled electricity generation. L‐Asp can significantly enhance this process by reducing the critical relative humidity of mixed salts, thereby exhibiting a stable open circuit potential and short‐cut current of ≈ 0.51 V and 10.6 µA within continuous 800 min. In conclusion, this work not only provides innovative approaches for upcycling high‐salinity wastewater but also explores novel applications for L‐Asp.