In nature, the chemical energy and electrons stored in ATP and NADPH generated during irradiation can facilitate biochemical reactions under dark conditions. However, in artificial photoreaction systems, it is still very difficult to perform photoreactions under dark conditions due to the fact that the photogenerated charge pairs can recombine immediately upon ceasing the irradiation. Preventing the recombination of photogenerated charge pairs still constitutes a major challenge at present. Here, it is reported that functionalized carbon nitride nanomaterials having many heptazine rings with a positive charge distribution, which can tightly trap photogenerated electrons, efficiently prevent the recombination of photogenerated charges. These stored charges are exceedingly long-lived (up to months) and can drive photopolymerization without light irradiation, even after one month. The system introduced here demonstrates a new approach for storing light energy as long-lived radicals, enabling photoreactions under dark conditions.