금속-유기 골격체(MOF) 유래 비정질 탄소 나노튜브 내 기능성 나노입 자의 In-Situ 봉입 : 환경 웅용을 위한 다기능.지속가능 촉매 = In Situ Confinement of Functional Nanoparticles within Amorphous Carbon Tubes Derived from Metal- Organic Frameworks: A Multifunctional and Sustainable Catalysts for Environmental Applications

다국어 초록 (Multilingual Abstract)

Encapsulating functional nanoparticles within non-crystalline carbon tubes (nCTs) has emerged as an effective strategy for creating robust heterogeneous catalysts. Such confined systems provide numerous advantages, including a high surface-to-volume ratio, abundant dangling bonds, strong electrical conductivity, and excellent long-term stability. In this study, a straightforward yet efficient approach was introduced to embed Cu/CuxO (x = 1, 2) nanocomposite particles inside carbon tubes (CTs) that were derived from the metal–organic framework (MOF) Cu-BTC, used here as a single precursor. The in situ formation and confinement process successfully prevented particle agglomeration and ensured uniform dispersion of the active copper phases within a conductive carbon framework.
A morphology-controlled synthesis route was first employed to prepare the precursor, followed by controlled thermal treatment to obtain the final product. Because temperature strongly influences phase evolution, the effects of synthesis temperature and heating ramp rate on the distribution of Cu, Cu2O, and CuO species confined within the nCTs were carefully examined. Systematic phase-engineering studies revealed that precise thermal control allowed the selective stabilization of desired Cu/Cu2O/CuO ratios, thereby improving electrical conductivity, strengthening interfacial contact, and enhancing catalytic efficiency. The confined architecture not only stabilized metastable copper oxide phases but also promoted rapid charge transfer and maintained structural integrity during long-term electrochemical and photocatalytic operation.
The optimized Cu2O/CuO@CT electrode exhibited remarkable electrocatalytic activity, delivering a current density of 10 mA cm⁻2 at overpotentials of 168 and 284 mV for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), respectively. The corresponding Tafel slopes, 73 mV dec⁻1 for HER and 62 mV dec⁻1 for OER, demonstrated excellent reaction kinetics. An electrolyzer assembled from these electrodes achieved 10 mA cm⁻2 at a cell potential of only 1.57 V. Density functional theory (DFT) calculations, consistent with experimental observations, indicated that the enhanced activity originated from the uniform distribution of Cu/CuxO nanoparticles within the carbon framework, which increased active site density, improved electron transport, and introduced beneficial confinement effects.
In addition, the Cu/Cu2O@CT composite displayed outstanding photocatalytic behavior, degrading 98% and 92% of typical cationic and anionic dyes within 80 min.—nearly double the efficiency of TiO2 catalysts. The kinetic rate constant was about seventeen times greater than that of simple photolysis. This improvement arose from synergistic effects such as uniform nanoparticle confinement, efficient interfacial charge migration, broadened visible-light absorption, and superior recyclability. Overall, the MOF-derived confinement strategy presented here establishes a practical and scalable path for constructing multifunctional Cu/Cu2O/CuO catalysts. Controlling phase evolution within confined carbon architectures proves to be a powerful route to tailor catalytic performance across both electrochemical and photochemical systems.
Keywords: Catalysis; Semiconductors; MOFs materials; Nanocomposites; Water splitting; HER/OER, Photocatalysis, Wastewater treatment.

목차 (Table of Contents)

• Chapter-1: General Introduction 1
• Chapter-2: MOF-Derived In-Situ Confinement of Copper/Copper Oxide Nanoparticles Inside a Carbon Tube: A Facile Morphologically Controlled Synthesis Strategy for Superior Visible-Light-Driven Photocatalytic Efficiency 13
• Chapter 3: Temperature and Ramp Rate-Controlled Phase Engineering of Copper Oxides in Non-Crystalline Carbon Tubes for Enhanced Alkaline Water Splitting 65
• 초록 114