沼渣生物炭热再生及其氨氮吸附性质
周旸, 严丽丽, 张文娟, 饶品华
【无机化学学报】doi: 10.11862/CJIC.20250032
在研究沼渣生物炭吸附氨氮(NH4+)的特性及机理的基础上,我们重点探讨了饱和沼渣生物炭的热再生性能,并研究了热再生参数(再生温度、再生时间、升温速率、保护气以及气体流速)对生物炭吸附性能的影响机制。沼渣生物炭对NH4+的吸附量可达19.12 mg·g-1,符合Langmuir模型,吸附机理主要是表面配位和离子交换反应。最佳热再生参数如下:温度为200 ℃,保护气为N2,流速为0.5 L·min-1,以5 ℃·min-1的升温速率再生1 h。饱和生物炭首次吸附再生率为99.59%,经10次吸附-再生循环后,吸附再生率仍达89.55%,失重率小于5%。通过热重-红外联用仪(TG?IR)、傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)、比表面及孔隙度分析和扫描电子显微镜(SEM)等多种手段进行表征,结果表明,多次循环热再生可破坏饱和生物炭表面的C=O、—OH和—COOH等含氧官能团,同时部分吸附位点被永久占用,导致吸附再生率逐渐下降。热再生可实现饱和生物炭中绝大部分氨氮的热解脱附,有效恢复生物炭孔隙结构和表面含氧官能团的吸附位点。
关键词: 沼渣, 生物炭, 热再生, 氨氮
Efficient regeneration of waste LiNi0.5Co0.2Mn0.3O2 cathode toward high-performance Li-ion battery
Hengyi ZHU, Liyun JU, Haoyue ZHANG, Jiaxin DU, Yutong XIE, Li SONG, Yachao JIN, Mingdao ZHANG
【无机化学学报】doi: 10.11862/CJIC.20240358
An efficient interlocking process was developed, including acid leaching, co-precipitation, and heat treatment, to regenerate waste LiNi0.5Co0.2Mn0.3O2 (NCM523) materials. DL-tartaric acid and formic acid were used as leaching systems, and the leaching efficiencies of Li, Ni, Co, and Mn reached about 98%. The leaching solution was added to the oxalic acid solution for a co-precipitation reaction, and then the regeneration of the material was realized through heat treatment. The regenerated NCM523 material exhibited an excellent layered structure and uniform elemental distribution. When employed as a cathode material for LIBs, the regenerated NCM523 exhibited a discharge-specific capacity of 168.5 mAh·g-1 at 0.1C (18 mA·g-1), which is comparable to the performance of fresh NCM523. Furthermore, the regenerated NCM523 demonstrated a capacity retention of 93.09% after 100 cycles at 0.5C.
关键词: Li-ion battery, regeneration, leaching, co-precipitation, heat treatment
再生纤维素与氧化还原石墨烯复合薄膜在湿气发电与镁空气电池协同发电上的应用
雷丽莎, 雍玮, 陈怡婷, 王奕博, 黄文潮, 赵俊焕, 翟忠杰, 丁杨彬
【无机化学学报】doi: 10.11862/CJIC.20240202
设计了一种绿色的再生废纸纤维素(RCewp)与氧化还原石墨烯(rGO)复合的薄膜(RCewp/rGO)并将其作为活性材料,其在7 000 s的循环中稳定输出的最大峰值电流为10 μA,且在100 Ω负载下的输出功率最高可达2.34 μW·cm-2。同时,研究表明金属集流体对湿气发电的影响显著,其中不锈钢集流体在70%的相对湿度(RH)条件下,产生的开路电压最大可达53 mV,因为集流体的氧化还原反应在湿气作用下增强了电流和电压的输出。此外,该湿气发电薄膜与镁空气电池结合时表现出优异的性能:在50%RH下,RCewp/rGO电极能够产生高达1.37 V的开路电压(Voc)和0.132 mA·cm-2的短路电流密度;当RH升高至90%时,开路电压进一步增大至1.57 V,短路电流密度达到64.2 mA·cm-2。而对于未与湿气发电薄膜相连的Mg-滤纸-Ni电极,其输出功率和短路电流密度仅为3.76×10-4 mW和0.306 μA·cm-2
关键词: 湿气发电, 镁空气电池, 协同发电, 再生纤维素

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