Regulating Charge Transfer of Lattice Oxygen in Single‐Atom‐Doped Titania for Hydrogen Evolution

Abstract

Single‐atom catalysts have attracted much attention. Reported herein is that regulating charge transfer of lattice oxygen atoms in serial single‐atom‐doped titania enables tunable hydrogen evolution reaction (HER) activity. First‐principles calculations disclose that the activity of lattice oxygen for the HER can be regularly promoted by substituting its nearest metal atom, and doping‐induced charge transfer plays an essential role. Besides, the realm of the charge transfer of the active site can be enlarged to the second nearest atom by creating oxygen vacancies, resulting in further optimization for the HER. Various single‐atom‐doped titania nanosheets were fabricated to validate the proposed model. Taking advantage of the localized charge transfer to the lattice atom is demonstrated to be feasible for realizing precise regulation of the electronic structures and thus catalytic activity of the nanosheets.

Single‐Atom or Dual‐Atom in TiO2Nanosheet: Which is the Better Choice for Electrocatalytic Urea Synthesis?

“…Pd 1 −TiO 2 were fabricated by using TiO 2 nanosheets with Ti‐deficiencies as precursors, its synthetic procedure (Figure S1, Supporting Information) was based on the our previous report on synthesis of Pt 1 −TiO 2 [7] . In contrast, Pd 1 Cu 1 −TiO 2 was prepared by using single‐atom Cu 1 −TiO 2 nanosheets (Figure S2, Supporting Information) as precursors, its synthesis process (Figure S3, Supporting Information) was based on the our previous report on synthesis of TM 1 −TiO 2 (TM denotes to transition metal) [8] . The morphologies of as‐made Pd 1 Cu 1 −TiO 2 and Pd 1 −TiO 2 were characterized by various advanced techniques.…”

“…To address above issue, herein, we report on two kinds of catalysts through a modified vacancy‐anchorage method: [7] single‐atom Pd 1 −TiO 2 and dual‐atom Pd 1 Cu 1 −TiO 2 nanosheets with oxygen vacancies ( O V ) (Figure 1). The above synthetic routes are based on our previous reports [7, 8] on synthesis of single‐atom nanosheets. We demonstrate that both Pd 1 Cu 1 dual‐atom and O V serve as the active centers in Pd 1 Cu 1 −TiO 2 , which differs from Pd 1 and O V counterparts in Pd 1 −TiO 2 .…”

Inverse ‘intra-lattice’ charge transfer in nickel–molybdenum dual electrocatalysts regulated by under-coordinating the molybdenum center

“…2 Charge transfer is commonly induced by heteroatom doping, defect density modications, altering the single atom coordination or by changing the surface molecular functionalization. The most familiar occurrence is charge redistribution between the metal and non-metal, 3,4 due to their disparate electronegativity (EN), which is the power of an atom to attract electrons in a given orbital towards itself. 5,6 The rule of thumb is the acceptance of electrons by an atom with a vacant orbital from a neighboring atom with a lled orbital, to stabilize its eigen state.…”

Electronic interaction between transition metal single-atoms and anatase TiO2 boosts CO2 photoreduction with H2O

“…Earth-abundant first-row transition metal atoms (Fe, Co, Ni, Mn and Cu), which are highly effective as active catalytic species for the conversion of small molecules such as H 2 O, O 2 , CO 2 and N 2 , have attracted significant research interest in designing high-performance single-atom catalysts (SACs) comprising earth-abundant elements. 20–33 Likewise, a number of atomically dispersed metals on a photocatalyst surface have emerged as effective platforms for various photochemical reactions. These include H 2 evolution, 24–30 CH 4 conversion, 19 N 2 reduction, 31 and CO 2 reduction, 16,34–37 demonstrating the versatility of a single atom as an effective cocatalyst system.…”

“…20–33 Likewise, a number of atomically dispersed metals on a photocatalyst surface have emerged as effective platforms for various photochemical reactions. These include H 2 evolution, 24–30 CH 4 conversion, 19 N 2 reduction, 31 and CO 2 reduction, 16,34–37 demonstrating the versatility of a single atom as an effective cocatalyst system. However, the single-atom photocatalyst is still in its infancy and the determining factor that influences the photocatalytic performance is not well understood.…”