Can environmental regulation foster incremental enhancement and quality improvement in green technological innovation under the background of the digital development?

China is facing increasingly severe challenges of environmental pollution and resource depletion in pursuit of economic growth. Consequently, it is imperative to investigate the influence of environmental regulations on the enhancement of quantity and quality in urban green technological innovation, alongside the role of the digital development. By leveraging panel data of 230 cities in China from 2011 to 2021, this study systematically examines the impact of environmental regulation on the quantity and quality of green technological innovation, and the moderating effect of the digital development. Findings reveal that as the level of environmental regulation rises, not only the quantity but also the quality of urban green technological innovation increase. Furthermore, the digital development further strengthens the promotional effect of environmental regulation on the quantity of urban green innovation, yet insignificantly impacting innovation quality. It is noteworthy that the favorable environment for digital development enhances the promotional effects of environmental regulations on both the quantity and quality of urban green innovation. Simultaneously, as the level of the digital development advances, environmental regulation will ultimately significantly promote the improvement in the quality of green innovation.