Heteroleptic polypyridyl Ru complexes MMR‐1 and MMR‐2 containing 2‐(methylthio)thienyl and 2‐(4‐methoxyphenyl)thienyl units on the antennas of ancillary ligands, respectively, were designed, synthesized, and characterized as sensitizers for dye‐sensitized solar cells. The maximum absorption wavelength of MMR‐1 is more red‐shifted than that of MMR‐2, but MMR‐2 has a higher molar extinction coefficient, leading to better light harvesting. Under the same device‐fabrication conditions, the photovoltaic performances of these sensitizers were evaluated while anchored on mesoporous TiO2 and compared to that of the benchmark N719. Both MMR‐1 and MMR‐2 exhibited comparable or even higher solar‐to‐electric conversion efficiencies η with respect to N719 when employed as photosensitizers in DSSCs. Compared to MMR‐1, MMR‐2 exhibited better overall conversion efficiency, which was attributed to the electron‐donating effect of the 4‐methoxyphenyl group and the better absorptivity by harvesting higher‐energy photons. Complex MMR‐2 also showed higher open‐circuit voltage VOC than MMR‐1, which is likely due to the extension of the antenna of the ancillary ligand by inserting a phenyl group, which leads to less dye aggregation. The photovoltaic performance of MMR‐2 was better, with a short‐circuit photocurrent density of 16.76 mA cm–2, a VOC of 0.673 V, a fill factor of 73.5 %, and an η value of 8.29 % with the addition of 0.5 m 4‐tert‐butylpyridine (TBP) compared to 8.18 % for N719.

Water pollution has been a significant challenge for the environment and human health. Dyes in water resources cause severe water pollution and block sunlight penetration through water, which impairs photosynthesis of aquatic plants as well as causes a significant alteration in ecological conditions of aquatic life. Dye-contaminated water sources can pose serious public health concerns, including toxicity, mutagenicity, and carcinogenicity among other adverse health effects. Therefore, it is imperative to develop efficient methods to remove dye contaminants from water sources. Synthetic polymers, due to their versatile chemical structure, size, and shape, could provide a tunable platform to remove dyes from contaminated sources. Herein, we report a polymer-mediated removal of textile dyes from aqueous solutions. A nitrogen-rich polymer, polycarbodiimide, efficiently removed anionic dyes from a dye-contaminated acidic solution. Upon dye removal, the polymer was regenerated through modulation of the solution pH. Further investigations showed that the polymer’s ability to remove dyes was dependent on solution pH and the topological polar surface area of the dyes. Thus, the molecular mechanism for polymer–dye interactions could be attributed to a combined ionic and hydrophobic interaction. The effects of pH, ionic strength, dye concentration, and composition were also investigated. Removal of dyes from contaminated aqueous resources is important in reducing environmental pollutants and mitigating environmental and health impacts. The findings from this study provide insights into the development of polymeric materials to remove soluble dyes from contaminated water to foster environmental and water sustainability.