激光诱导石墨烯/ITO异质结构通过电离光伏效应实现自供电离子传感

摘要：高性能离子传感对推进生理与环境监测系统至关重要。尽管已开发出多种离子传感策略，但仍需探索兼具卓越性能与极低能耗的新型方案。本文，深圳技术大学史济东副教授、南方科技大学Lingyu Zhao等研究人员在《Chemical Engineering Journal

1成果简介

高性能离子传感对推进生理与环境监测系统至关重要。尽管已开发出多种离子传感策略，但仍需探索兼具卓越性能与极低能耗的新型方案。本文，深圳技术大学史济东副教授、南方科技大学Lingyu Zhao等研究人员在《Chemical Engineering Journal》期刊发表名为“Laser-induced graphene/ITO heterostructure for self-powered ion sensing via ionovoltaic effect”的论文，研究提出一种基于激光诱导石墨烯（LIG）与铟锡氧化物（ITO）异质结的自供电离子传感器。

该传感器利用LIG纳米通道的离子伏特效应及LIG/ITO界面功函数对齐特性，在加入盐溶液时可自发产生电压尖峰。在10⁻³M至2M的宽离子浓度范围内，针对多种电解质，尖峰幅度随离子浓度呈稳定递增趋势。通过多项性能对比分析与表面表征，全面探究了该离子伏特传感器的运作原理。该传感器不仅能测量人体汗液与海水的盐度，更展现出在生理及环境传感领域的广泛适用性。其卓越的离子传感性能、自供电特性，结合激光直接书写（LDW）技术实现的可扩展制备工艺，使这款新型离子传感器具备集成于下一代智能电子设备的巨大潜力。

2图文导读

图1. Design, preparation and characterization of the LIG/ITO ionovoltaic sensor. (a) The schematic illustration of the ionovoltaic power generation process within the LIG/ITO heterostructure. (b) The schematic illustration of the device layout. (c) The optical image of the device. (d) The schematic illustration of the device structure in cross-sectional view. (e) The schematic illustration of the device fabrication process. (f) The optical image of an as-prepared LIG pattern, with the narrowest line width marked. (g) The SEM image of the as-prepared LIG. (h) The contact angle tests of the LIG undergoing different period of O2 plasma treatment.

图2. The performance of the ionovoltaic sensor. (a) The voltage output of the device upon the addition of 10 mM NaCl solution for 7 cycles. (b) The magnified view of a single voltage spike, characterizing the response and recovery time. (c) The spike amplitude upon the addition of NaCl solution with different concentration. (d) The 4 types of saline solutions for ionovoltaic sensing in this work. (e) The sensitivity of the ion sensor for the 4 types of saline solutions. (f) The comparison of ionovoltaic outputs for 3 mM NaCl solution and DI water. (g) The detection limit for the 4 types of saline solutions. (h) The stability test of the device for 7 consecutive days.

图3. The influential factors on the device's ionovoltaic properties. (a) The voltage outputs for devices with the LIG prepared by varied laser power. (b) The voltage outputs for devices with the LIG prepared by varied laser scanning rate. (c) The voltage outputs for devices undergoing different period of O2 plasma treatment. (d) The voltage outputs for devices coated by Au layer with different sputtering time. In (a)-(d), the time period between ticks in x-axis is 20 s. (e) The comparison of the voltage outputs for the devices with ITO and Au as the counter electrode. (f) The schematic illustration of ionophore modification of the LIG. (g) The comparison of the voltage outputs for the devices without/with ionophore modification of the LIG. (h) The schematic illustration of the LIG-ITO device. (i) The schematic illustration of the LIG-LIG device. (j) The comparison of the voltage outputs for the LIG-ITO and LIG-LIG device.

图4. The investigation of the working principle of the ionovoltaic sensor. (a) The schematic illustration of the electrical potential generation mechanism. (b) The change of carrier concentration within LIG with the ion concentration of NaCl solution. (c) The comparison of surface zeta potential and surface carrier mobility between the device with and without 30 s O2 plasma treatment. (d) The XPS characterization of LIG without, undergoing 5 s and undergoing 30 s O2 plasma treatment. (e) The XPS characterization of LIG without, after 10 s and after 30 s Au deposition.

图5. The application of the ionovoltaic sensor. (a) The perspiration status of a person. (b) The ionovoltaic output of the sensor in response to sweat with different salinity. (c) The schematic illustration of seawater filtration and salinity analysis of the filtrate. (d) The voltage output of the sensor in response to the seawater sample and filtrates undergoing different cycles of filtration. (e) The comparison of the voltage output between the filtrates undergoing 5 filtration cycles and DI water.

3小结

综上所述，作者设计了一种基于LIG/ITO异质结的自供电离子传感器。该器件利用LIG纳米通道的离子伏特效应及LIG/ITO界面功函数对齐特性，在加入盐溶液时可产生显著电压输出，并在多种盐溶液中实现了浓度与电压的稳定关联（浓度范围约为10⁻³-2M）。该器件在实际场景中成功应用于人体汗液与海水盐度测量，展现出在健康监测与环境监测领域的广阔前景。其采用直接激光刻写技术实现可扩展制备与精密图案化，这一关键优势使其易于集成至复杂电子系统。当前局限在于为适应高温热固化工艺而采用玻璃基板，限制了可穿戴应用场景。后续研究将致力于降低聚酰亚胺的制备温度，以实现柔性基板的应用。总而言之，本研究不仅设计出具有广阔应用前景的多功能离子传感平台，更深化了对离子-固体基本相互作用机制的理解，为先进离子伏特器件的后续设计提供了指导。

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