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The intensive use of fossil fuels has profound impacts on all ecosystems, primarily contributing to global warming through greenhouse gas emissions. To mitigate these impacts, alternative energy sources like hydrogen are crucial. In this study, azo cross‐linked polymer with 4‐aminophenyl sulfone and resorcinol were synthesized by a green synthesis method. The polymer was extensively characterized by Fourier‐transform infrared spectroscopy, Brunner‐Emmett‐Teller analysis, thermogravimetric analysis, and scanning electron microscopy‐energy dispersive x‐ray spectroscopy analyses. Subsequently, the catalytic performance of the polymer in hydrogen production from NaBH4 via methanolysis was investigated. At this stage, the parameters affecting hydrogen production (catalyst and NaBH4 amounts, MeOH volume and temperature) were systematically studied to determine optimum conditions. The maximum HGR values of the polymer was 13,100 and 27,000 mL min−1 gcat−1 at 30 and 60°C, respectively and its activation energy was 10.45 kJ mol−1. After optimization, the reusability of azo polymer was tested with 5 cycles. The theoretical volume of hydrogen was produced in all 5 cycles. But with each cycle, the hydrogen production time increased. The main purpose of this study was to demonstrate novel azo‐linked polymers with high catalytic activity in hydrogen production. The results revealed significant potential of the polymer for hydrogen generation. Overall, this research highlights the promising role of azo cross‐linked polymers as effective catalysts for hydrogen production, offering new perspectives and pathways towards sustainable energy solutions. [ABSTRACT FROM AUTHOR]

In this paper, a class of porous organic polymers (POPs) of p -hydroxy azobenzene with a mesoporous structure was designed and synthesized by a –N N– coupling reaction of tetraamino-metal phthalocyanine (MTAPc, where M = Co, Ni or Cu) with hydroquinone (namely Azo-MHQ, where M = Co, Ni or Cu). The Azo-MHQ materials possessed good thermal stabilities, excellent dispersibilities in water, polar and non-polar organic solvents, as well as excellent chemical stabilities. Among them, Azo-CuHQ showed an outstanding iodine trapping ability in an iodine solution and vapor with saturated adsorption capacities of 1347.47 mg g−1 and 118 wt%. In addition, Azo-CuHQ also showed a high adsorption capacity for methylene blue (MB) with the adsorption amount of 191.21 mg g−1. Furthermore, by loading Azo-CuHQ onto polyethersulfone (PES) membrane, the water permeability of the obtained membranes reached 147.03 L m−2 h−1 bar−1, and the retention rate of Ag in a very low concentration solution of 20 ppm was 56.8 %. Additionally, a thorough analysis of the Azo-CuHQ adsorption and separation mechanism was conducted. A novel approach to the design and synthesis of a class of materials with multifunctional adsorption and separation capabilities is presented in this research. [Display omitted] • Low-temperature synthesis of Azo-MHQ in an aqueous solution is an effective method. • Azo-CuHQ exhibits an excellent adsorption capability for iodine molecule. • Azo-CuHQ can preferentially adsorb MB via hydrogen bonds. • By loading Azo-CuHQ onto PES, the Ag retention rate is 56.80 %. [ABSTRACT FROM AUTHOR]

Surface‐relief‐gratings (SRGs) of azo polymers and azo molecular glasses have attracted considerable interest for their erasable and reconfigurable characteristics. Herein, the optical erasure of soft‐lithographically duplicated SRGs of an azo polymer (BP‐AZ‐CN) and an azo molecular glass (IAC‐4) is investigated to tackle a long‐standing problem from “memory” effect existing in optically inscribed SRGs. The optical erasure is performed by single laser beam irradiation at wavelength of 488 nm with different polarizations, and the erasing behavior is thoroughly investigated by real‐time diffraction efficiency measurement and atomic force microscopy (AFM) observation. Showing no obvious dependence on the light polarizations, the optical erasure of IAC‐4 grating is a relatively fast process, and the original one can be completely erased and recreated. In contrast, the erasure of BP‐AZ‐CN grating is not only much slower, but also strongly correlated with the light polarizations. Upon the p‐polarized light irradiation, the grating profiles are substantially distorted during the erasure with a significant difference in that of the s‐polarized light irradiation. The gratings cannot be completely erased by the lights with all the polarizations. The erasure behavior is found to be determined by the effects of surface tension and mass transfer along the light polarization direction to different extents.