Nonconjugated polymer dots (PDs) without largely conjugated structures entitle their advantages such as environment friendliness, nontoxicity, and intrinsic fluorescence. However, color-tunable PDs remain a challenge. Herein, polyvinyl pyrrolidone (PVP) and ascorbic acid (AA) are used to synthesize nonconjugated PDs, namely, PA PDs with intensive blue emission. The introduction of a third component, m-phenylenediamine (MPD), redshifted the emission to green. The asprepared color-tunable blue to green emissive PDs exhibit excellent properties, whether in solution or in solid state, originated from the mechanism of clusteringtriggered emission (CTE) induced by the overlap of electron-rich atoms, the strong inter/intrachain interaction. The quantum yields of blue and green PDs reached up to 15.07% and 28.22%, respectively. Furthermore, PA PDs were successfully applied to the highly efficient photocatalytic degradation for dyes: methylene blue (MB) and methyl orange (MO) were degraded by 89.9% and 93.8% within 20 min under visible light, respectively.

Main observation and conclusion A novel and facile approach towards highly luminescent CuNCs@MMI (2‐mercapto‐1‐methylimidazole) has been developed within 30 s with the assistance of ionic liquids (ILs)—[Bmim]BF4. FT‐IR spectra, Zeta potential, TEM and SEM images showed that the as‐prepared CuNCs@MMI within [Bmim]BF4 could assemble into well‐ordered triangle supramolecular nanostructures via electrostatic interaction. In addition, pH‐responsion of CuNCs@MMI in photoluminescence intensity indicated the great potential for pH sensing applications.