One‐Step Prepared Water‐Resistant Organic–Inorganic‐Hybrid Perovskite Quantum Dots with Zn–Oxygen Vacancies for Attempts at Nitrogen Fixation

Abstract

Applying organic–inorganic hybrid perovskite quantum dots (PQDs) to photocatalytic nitrogen fixation is hindered long‐term by the inherent instability in water and tedious preparations. Here, to realize PQD‐catalyzed photocatalytic N2 reduction reaction (NRR), water‐resistant PQDs are simply prepared through one‐step electrospray synthesis in microseconds. During the fast electrospray, PQDs of Zn/PbO‐doped methylammonium lead bromide (Zn/PbO/PC–Zn/MAPbBr3, MA: CH3NH3) are prepared and part‐encapsulated by polycarbonate. The synthesis maintains good water resistance, whose restriction on charge transport is overcome skillfully. Simultaneously, substitution of Zn with Pb on water‐resistant surface is also achieved, which fabricates new Zn–oxygen vacancies (Zn‐OVs) with Zn/PbO–Zn/MAPbBr3 type I heterojunction. This facilitates efficient electron transfer from internal heterojunction interface of Zn/MAPbBr3 PQDs to the surface of Zn/PbO. Demonstrated by theoretical calculations, Zn‐OVs promote chemisorption and polarization of N2. In addition, s‐electrons in exposed Zn become active due to changes of electron filling of Zn orbitals under OVs’ co‐doping. Thus, photocatalytic N2 reduction reaction catalyzed by organic–inorganic hybrid PQDs is first achieved in aqueous phase without sacrificial agents being added. This initiates possibilities for photocatalytic applications of organic–inorganic hybrid PQDs in aqueous phase.

Interspersed Bi Promoting Hot Electron Transfer of Covalent Organic Frameworks Boosts Nitrogen Reduction to ammonia

“…+ with the coupling constant of 52.2 Hz when 14 N 2 gas was introduced, whereas the isotopic labeled item showed the doublets of 15 NH 4 + with the coupling constant of 73.1 Hz when using 15 N 2 gas. [49] These results verified that the generated NH 4 + indeed originated from the feeding N 2 .…”

Semiconducting Quantum Dots for Energy Conversion and Storage

“…Gao et al. [ 183 ] used organic–inorganic hybrid perovskite QDs for photocatalytic NRR in solution without sacrificial agents. Perovskite QDs of Zn‐PbO‐doped methylammonium lead bromide (Zn‐PbO/polycarbonate/Zn‐CH 3 NH 3 PbBr 3 ) maintained favorable water resistance.…”

Colloidal FAPbBr3 perovskite nanocrystals for light emission: what's going on?

“…171 While earlier studies were focused on the Cs-based 172,173 or MA-based 174,175 perovskites for the Pb-Sn mixed composition, FAPb 1Àx Sn x Br 3 NCs 176,177 have also gained momentum recently, along with partial Pb replacement by other metals in the perovskite structure. [178][179][180][181] Cai et al reported the facile synthesis of FAPb 1Àx Sn x Br 3 NCs at RT using a modified LARP approach. 155 They found that the crystal structure remained cubic until 50% of Pb had been replaced by Sn; however, on further increasing the Sn concentration, the cubic phase partially lost its high symmetry structures.…”