Balakrishnan Akash, Vijaya Suryaa K, Tripathy Hritankhi, Trivedi Suverna, Kumar Arvind, Chinthala Mahendra
Process Intensification Laboratory, Department of Chemical Engineering, National Institute of Technology Rourkela, Odisha 769 008, India.
Environmental Pollution Abatement Laboratory, Department of Chemical Engineering, National Institute of Technology Rourkela, Odisha 769 008, India.
J Colloid Interface Sci. 2024 Jun;663:1087-1098. doi: 10.1016/j.jcis.2024.02.110. Epub 2024 Feb 22.
The development of highly reusable, affordable, and durable photocatalysts for the production of hydrogen peroxide (HO) remained a challenge. In this study, a homojunction photocatalyst (SPGCN) is constructed between phosphorylated g-CN (PCN) and sulfur self-doped g-CN (SCN) using a simple wet impregnation method. Later, the obtained SPGCN homojunction is transformed into hydrogel beads using carboxymethyl cellulose via an effective cross-linking strategy (SPGCN/CMC). The photocatalytic beads displayed a phenomenal HO production of 3.5 mM under visible light illumination for 60 min. The SPGCN/CMC hydrogel beads showed a maximum reusability of 10 cycles with a decline of 1.5 mM HO production. The improved photocatalytic efficiency is indicated by strengthened utilization of visible light via tuning of the band gap, suppressed recombination of electron-hole pairs, and higher separation efficiency through the effective construction of Z-scheme between the phosphorylated carbon nitride and the sulfur-self-doped carbon nitride present in the SPGCN/CMC beads. The mechanistic studies affirmed the dominant role of superoxide radicals in HO production. The photocatalytic HO production followed a highly selective two-electron reduction reaction. Overall, this study highlights the efficient engineering of carbon nitride-based materials towards artificial photosynthesis.
开发用于生产过氧化氢（HO）的高可重复使用、价格合理且耐用的光催化剂仍然是一项挑战。在本研究中，采用简单的湿浸渍法在磷酸化g-CN（PCN）和硫自掺杂g-CN（SCN）之间构建了一种同质结光催化剂（SPGCN）。随后，通过有效的交联策略，使用羧甲基纤维素将获得的SPGCN同质结转化为水凝胶珠（SPGCN/CMC）。光催化珠在可见光照射60分钟下显示出3.5 mM的惊人过氧化氢产量。SPGCN/CMC水凝胶珠显示出最大10次循环的可重复使用性，过氧化氢产量下降1.5 mM。通过调节带隙增强可见光的利用、抑制电子-空穴对的复合以及通过在SPGCN/CMC珠中存在的磷酸化氮化碳和硫自掺杂氮化碳之间有效构建Z型结构提高分离效率，表明光催化效率得到了提高。机理研究证实了超氧自由基在过氧化氢生成中的主导作用。光催化过氧化氢生成遵循高度选择性的双电子还原反应。总体而言，本研究突出了基于氮化碳材料在人工光合作用方面的高效工程设计。
