Coordination polymers (CPs) are a diverse class of multi-dimensional compounds that show promise as photocatalysts for degrading dyes in polluted water. Herein, a new 1D Cd(II)-based coordination polymer with the formula [Cd(bpyp)(nba)₂] (1) (bpyp = 2,5-bis(pyrid-4-yl)pyridine and Hnba = 4-nitrobenzoic acid) is synthesized and characterized. In 1, the two carboxyl groups of two different nba⁻ ligands show μ₂-η¹:η¹ and μ₁-η¹:η¹ coordination modes to connect the Cd^II centers and sit on either side of the chain along the b direction. The produced CP 1 was utilized as the photocatalyst in the process of the photodegradation of methyl blue (MB), methyl orange (MO), rhodamine B (RhB), and methyl violet (MV) dyes when exposed to UV light. The photocatalytic degradation activities of CP 1 were analyzed, and the results suggest that it exhibits an extraordinary efficiency in the degradation of MB, MV, MO, and RhB. RhB has a 95.52% efficiency of degradation, whereas MV has a 58.92% efficiency, MO has 35.44%, and MB has 29.24%. The photodecomposition of dyes is catalyzed mostly by •O₂⁻ and •OH⁻, as shown by research involving the trapping of radicals.

The latest advancements in MOF-based three-dimensional macrostructures, encompassing fascinating characteristics, preparation strategies, characterization methods, and environmental applications, are examined.

The need to minimize carbon emissions and improve sustainable energy systems has stimulated significant research into multifunctional materials. This work presents a unique MXene@MOF and sodium alginate hydrogel composite as an electrocatalyst in energy storage and conversion. The Max-phase titanium niobium aluminum carbide (TiNbAlC) was etched to remove Al layers, producing MXene (TiNbCTx). The MXene nanosheets were dispersed in methanol, ultrasonicated, and mixed with polyvinylpyrrolidone (PVP). Subsequently, Zn(NO₃)₂·6H₂O and Co(NO₃)₂·6H₂O were added, followed by 2-methylimidazole, and stirred for 2 h. After 4 h, centrifugation, washing, and freeze-drying produced TiNbC@MOF. This composite was further incorporated into a sodium alginate hydrogel to construct TiNbC/MOF@SA-H. Besides, the characterization included SEM, EDX, XRD, FTIR, AFM, TGA, and XPS analysis. The performance of the electrocatalyst was assessed for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in an alkaline medium (1 M KOH). TiNbC/MOF@SA-H demonstrated excellent capacitance, high rate capability, and stability over 1000 cycles. TiNbC/MOF@SA-H demonstrates enhanced OER electrocatalytic performance relative to the reference IrO₂ and the composite TiNbC/MOF, exhibiting low overpotentials of 185, 188 and 204 mV at current densities of 10, 20 and 50 mA cm⁻², respectively. Additionally, it shows superior HER catalytic activity compared to other prepared samples, requiring only 17, 79 and 325 mV to achieve current densities of 10, 50 and 100 mA cm⁻², respectively. The material achieved an OER Tafel slope of 84 mV dec⁻¹ and a HER Tafel slope of 61.8 mV dec⁻¹ at a 1 V s⁻¹ scan rate.