The hazardous industrial effluent, enriched in organic dyes, produces environmental alarms of being resistant to natural degradation processes. Therefore, the development of sustainable, and cost-effective degradation processes is a vital demand. Here, we present a simple, scalable, and cost-effective methodology to synthesize polyimides from melem and dianhydrides monomers through a solvent-free, thermal condensation approach for effective photo-catalytic dye degradation. The synthesized polyimides were systematically characterized to investigate their surface functionality, crystallinity, morphology, surface area, porosity, and elemental composition followed by their photocatalytic activity. The obtained results confirmed that polyimides derived from melem with 2,2’-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (M-FDA) and 4,4’-oxydiphthalic dianhydride (M-ODPA) exhibited an efficient degradation of methylene blue up to 93 and 92%, respectively. Whereas, melem and naphthalene tetra-carboxylic dianhydride-based polyimide (M-NTDA) displayed relatively low-degradation ability after the same irradiation period of 75 min. The superior photocatalytic performances of M-FDA and M-ODPA polyimides have been attributed to their relatively low degree crystallinity, layered morphology, high nitrogen content; 26.07, 24.08%, respectively, with high pyridinic (N6) configurations; 69.48 and 64.14%, respectively; and improved surface areas of 2.6183 and 1.8441 m²g⁻¹ with sufficient pores which offer more reactive sites for interaction with dye molecules leading to superb photocatalytic activity. Hence, it can be concluded that besides extended π network structure, photocatalysis may be improved in photocatalyst materials by improving their physicochemical characteristics. The current endeavor is a great contribution to research community for developing suitable photocatalysts to degrade various other dyes and pollutants efficiently.

富含有机染料的危险工业废水会产生对自然降解过程具有抵抗力的环境警报。因此，开发可持续且具有成本效益的降解过程是至关重要的需求。在这里，我们提出了一种简单、可扩展且具有成本效益的方法，通过无溶剂的热缩合方法从蜜勒胺和二酐单体合成聚酰亚胺，以实现有效的光催化染料降解。系统地表征合成的聚酰亚胺以研究它们的表面官能度、结晶度、形态、表面积、孔隙率和元素组成，然后研究它们的光催化活性。获得的结果证实了衍生自蜜勒胺的聚酰亚胺与 2,2'-双-(3,4-二羧基苯基)六氟丙烷二酐 (M-FDA) 和 4, 4'-氧二邻苯二甲酸二酐 (M-ODPA) 表现出对亚甲蓝的有效降解率分别高达 93% 和 92%。而蜜勒胺和萘四甲酸二酐基聚酰亚胺 (M-NTDA) 在相同的 75 分钟照射时间后显示出相对较低的降解能力。M-FDA 和 M-ODPA 聚酰亚胺优异的光催化性能归因于它们相对较低的结晶度、层状形态、高氮含量；分别为 26.07、24.08%，具有高吡啶 (N6) 构型；分别为 69.48 和 64.14%；和改进的表面积 2.6183 和 1.8441 m 蜜勒胺和萘四羧酸二酐基聚酰亚胺 (M-NTDA) 在相同的 75 分钟照射时间后显示出相对较低的降解能力。M-FDA 和 M-ODPA 聚酰亚胺优异的光催化性能归因于它们相对较低的结晶度、层状形态、高氮含量；分别为 26.07、24.08%，具有高吡啶 (N6) 构型；分别为 69.48 和 64.14%；和改进的表面积 2.6183 和 1.8441 m 蜜勒胺和萘四羧酸二酐基聚酰亚胺 (M-NTDA) 在相同的 75 分钟照射时间后显示出相对较低的降解能力。M-FDA 和 M-ODPA 聚酰亚胺优异的光催化性能归因于它们相对较低的结晶度、层状形态、高氮含量；分别为 26.07、24.08%，具有高吡啶 (N6) 构型；分别为 69.48 和 64.14%；和改进的表面积 2.6183 和 1.8441 m² g ^-1具有足够的孔隙，为与染料分子的相互作用提供更多的反应位点，从而产生极好的光催化活性。因此，可以得出结论，除了扩展的 π 网络结构外，光催化剂材料的光催化性能还可以通过改善其物理化学特性来提高。目前的努力是对研究界的巨大贡献，以开发合适的光催化剂以有效降解各种其他染料和污染物。