Zn-based and Al-based MOF photocatalysts with abundant oxygen vacancies for fixing nitrogen effectively under mild conditions

• Zn- and Al-based MOF photocatalysts with effective nitrogen fixation were prepared simply. • Zn-bpydc and Al-bpydc produce ammonia at ambient temperature and pressure with rates of 796.1 µg g -1 h −1 and 684.0 µg g -1 h −1 . • Zn-bpydc and Al-bpydc produce a large number of oxygen vacancies under light conditions. • The 15 N 2 isotope experiments confirmed that the N element in synthetic ammonia came from N 2 . Photocatalytic nitrogen fixation is an environmentally friendly process for turning atmospheric nitrogen into ammonia under mild conditions. In this study, MOF photocatalysts Zn-bpydc and Al-bpydc with good nitrogen fixation effect were prepared by a simple one-pot method. The rates of ammonia generation for Zn-bpydc and Al-bpydc at normal temperature and pressure were 796.1 µg g -1 h −1 and 684.0 µg g -1 h −1 , respectively. The ESR test demonstrated that Zn-bpydc exhibits a higher concentration of oxygen vacancies than Al-bpydc, allowing it to chemically adsorb N 2 and construct an effective electron transport pathway, hence enhancing the catalyst’s photocatalytic activity. This study provides a simple, efficient and economical MOF photocatalysts that can contribute to sustainable development.