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Covalent organic frameworks (COFs) face limited processability challenges as photoelectrodes in photoelectrochemical water reduction. Herein, sub‐10 nm benzothiazole‐based colloidal conjugated reticular oligomers (CROs) are synthesized using an aqueous nanoreactor approach, and the end‐capping molecular strategy to engineer electron‐deficient units onto the periphery of a CRO nanocrystalline lattices (named CROs‐Cg). This results in stable and processable "electronic inks" for flexible photoelectrodes. CRO‐BtzTp‐Cg and CRO‐TtzTp‐Cg expand the absorption spectrum into the infrared region and improve fluorescence lifetimes. Heterojunction device engineering is used to develop interlayer heterojunction and bulk heterojunction (BHJ) photoelectrodes with a hole transport layer, electron transport layer, and the main active layers, using a CROs/CROs‐Cg or one‐dimensional (1D) electron‐donating polymer HP18 mixed solution via spinning coating. The ITO/CuI/CRO‐TtzTp‐Cg‐HP18/SnO2/Pt photoelectrode shows a photocurrent of 94.9 µA cm‒2 at 0.4 V versus reversible hydrogen electrode (RHE), which is 47.5 times higher than that of ITO/Bulk‐TtzTp. Density functional theory calculations show reduced energy barriers for generating adsorbed H* intermediates and increased electron affinity in CROs‐Cg. Mott‐Schottky and charge density difference analyses indicate enhanced charge carrier densities and accelerated charge transfer kinetics in BHJ devices. This study lays the groundwork for large‐scale production of COF nanomembranes and heterojunction structures, offering the potential for cost‐effective, printable energy systems. [ABSTRACT FROM AUTHOR]

Precise regulation of photogenic electron transfer path plays an important role in improving photocatalytic carbon dioxide reduction efficiency and product selectivity. Herein, under the guidance of density functional theory calculation, the interface chemical bond (CoN2 bond) at the atomic level is designed, and g‐C3N4/CoCo‐layered double hydroxide (LDH) heterostructure is manufactured. CoCo‐LDH with water oxidation ability and g‐C3N4 were combined to construct S‐scheme heterojunction with redox ability. The valence band and conduction band of g‐C3N4 and CoCo‐LDH are precisely connected by the interfacial CoN2 bond, which realizes the high‐speed transfer of electron transport. Despite the absence of cocatalyst, the heterojunction exhibits high water oxidation and carbon reduction capacity due to the precise regulation of CoN2 bonds. Theoretical calculations and experimental results show that the addition of CoCo‐LDH: reduces the oxidation overpotential of water to provide more H protons; regulates the delocalization charge of g‐C3N4; and reduces the energy barrier of the CO2 intermediate (*COOH) in the reduction half‐reaction. The results show that the selectivity of carbon‐based substances in the products was 100%, and the optimal CO yield was 71.39 μmol g−1 h−1, which is among the highest values of g‐C3N4‐based photocatalysts. [ABSTRACT FROM AUTHOR]

The reduction pathway of Co catalysts supported on untreated SiO2 along with two pretreated SiO2 support materials was investigated. In situ XRD studies clearly showed the likely reduction pathways of the cobalt oxides on the untreated SiO2, ethylene glycol pretreated SiO2, and annealing pretreated SiO2 supports. Ethylene glycol pretreated SiO2-supported Co (Co/E–SiO2) catalyst showed smaller metal crystallites, highly dispersed Co and high Co(hcp)/Co(fcc) ratio because of the high percentage of non-H-bonded silanols; however, the high percentage of the non-H-bonded silanols created a strong Co-SiO2 interaction which caused a low degree of reduction of CoO resulting in lower FT activity. In contrast, the annealing pretreated SiO2-supported Co (Co/A–SiO2) catalyst did not significantly increase the percentage of non-H-bonded silanols and Co(hcp)/Co(fcc) ratio when compared with Co/E–SiO2, but it exhibited a better catalytic activity during FTS. [ABSTRACT FROM AUTHOR]

The design course is an integral part of chemical engineering education. A novel approach to the design course was recently introduced at the University of the Witwatersrand, Johannesburg, South Africa. The course aimed to introduce students to systematic tools and techniques for setting and evaluating performance targets for processes, as well as gaining insight into how these targets can be achieved. The main objectives were efficient use of raw materials, energy and improved environmental performance (reducing CO2 emissions). The approach is to use fundamental principles--mass, energy and entropy--to identify limits of operation or targets. Unlike the traditional approach to process design where the flow sheet is normally chosen from existing literature or from prior knowledge, the flow sheet emerges from the analysis in this new approach. The course was well received by students and allowed the students to gain a better understanding of developing processes which are efficient and have less impact on the environment.