The effect of green technology innovation on air pollution from a quantity-quality perspective in China's large river...

Green technology innovation (GTI) plays a crucial role in promoting regional sustainable development, yet its mechanisms for mitigating air pollution remain insufficiently explored. This study investigates the spatio-temporal dynamics and spatial correlations of GTI and air pollution across China's major river basins, with a particular focus on differentiating the roles of GTI quantity and quality. Using the extended STIRPAT and spatial Durbin models, we examine nonlinear relationships, basin-specific heterogeneity, and spatial spillover effects. Results show that GTI quantity followed a core-periphery diffusion pattern, while GTI quality exhibited fluctuating trends with recent stabilization. An inverted "U" shaped relationship was observed between both GTI dimensions and PM_2.5 and PM₁₀ concentrations, locally and in neighboring areas. Notably, inflection points for GTI quantity lagged behind those for quality, and post-inflection pollution-reduction effects differed across basins-being stronger in the Yangtze River Basin for PM_2.5, but in the Yellow River Basin for PM₁₀. These findings highlight the differentiated mechanisms through which GTI affects air quality, offering valuable insights for targeted innovation policies and regional coordination in sustainable governance.