A Template Editing Strategy to Create Interlayer‐Confined Active Species for Efficient and Durable Oxygen Evolution Reaction

Abstract

highly active and stable OER electrocatalysts based on rational design strategies is a critical knot along the renewable energy roadmap of converting electrical energy into fuels and chemicals. In particular, electrochemical water splitting can directly utilize the renewable electricity for efficient and clean hydrogen production. [4] The energy conversion efficiency is seriously restricted by OER processes with muti-electron transformation and complex reaction routes. [5] Given this challenge, precious metal-based oxides (IrO 2 and RuO 2 ) were developed as the mainstream electrocatalysts and exhibited high catalytic performance at the harsh reaction condition, whereas scarcity and expensiveness hinder their applications for the large-scale hydrogen production. Therefore, a key bottleneck is to develop efficient and stable earth-abundant catalysts.Ideally, OER catalysts are expected to exhibit high-density accessible active sites, high ion permeability that allows the free movement of ions, and high structural stability for long-term operation. Most metal-based OER catalysts follow a redox couple-mediated water oxidation mechanism. [6] Metal ions usually serve as redox couples to reduce the OER overpotentials. [7] An ideal OER catalyst should offer an appropriate ligand environment with active Substantial overpotentials and insufficient and unstable active sites of oxygen evolution reaction (OER) electrocatalysts limit their efficiency and stability in OER-related energy conversion and storage technologies. Here, a template editing strategy is proposed to graft highly active catalytic species onto highly conductive rigid frameworks to tackle this challenge. As a successful attempt, two types of NiO 6 units of layered Ni BDC (BDC stands for 1,4-benzenedicarboxylic acid) metal organic frameworks are selectively edited by chemical etching-assisted electroxidation to create layered γ-NiOOH with intercalated Ni-O species. In such an interlayer-confined intercalated architecture, the large interlayer space with high ion permeability offers an ideal reaction region to sufficiently expose the OER active sites comprising high-density intercalated Ni-O species, which also suppresses the undesirable γ to β phase transformation, thus exhibiting efficient and durable OER activity. As a result, water oxidation can occur at an extremely low overpotential of 130 mV and affords 1000 h stability at 100 mA cm −2 . The strategy conceptually shows the possibility of achieving stable homogeneous-like catalysis in heterogeneous catalysis.

Green and sustainable bifunctional carbonized wood electrodes decorated with controlled nickel/α(β)-nickel(ii) hydroxide to boost overall water splitting

“…The OER curves of Ni/Ni(OH) 2 / CW consisted of the peaks of the oxidation of Ni(OH) 2 before oxygen evolution. 15,19,22,39,43,46,55,56 Ni(OH) 2 undergoes two types of oxidations to afford NiOOH: 477 and 558 cm −1 , which match well with those of g-NiOOH. 43,44,57 For the Ni/Ni(OH) 2 /CW-10 min, peaks appear at 482 and 563 cm −1 , which match well with those of b-NiOOH.…”

“…The higher oxidation state of Ni(OH) 2 in Ni/Ni(OH) 2 /CW-1 min can be oxidized to NiOOH easily, which acted as the active species for OER. 19,45,46 Additionally, the electron binding energy of Ni 2p 3/2 corresponding to Ni 0 decreased by ∼0.3 eV with an increase in the deposition time (Fig. 2e and S7 †).…”

“…a-Ni(OH) 2 demonstrates superior performance to that of b-Ni(OH) 2 owing to its conversion to g-NiOOH below the onset potential of water oxidation, providing the ideal catalytic species for OER. 46,59 Long-term performances of Ni/Ni(OH) 2 / CW-1 min were examined at a constant current density of 10 mA cm −2 for 10 h in 1.0 M KOH. Ni/Ni(OH) 2 /CW-1 min retained approximately 58% of its initial current density during continuous electrolysis for 10 h (Fig.…”

Electrochemical Production of Glycolate Fuelled By Polyethylene Terephthalate Plastics with Improved Techno‐Economics

“…Note that NaCl used here serves a vital role in accelerating the corrosion process. [39] X-ray diffraction (XRD) pattern (Figure 2b) displays several typical peaks that belong to 𝛾-NiOOH phase (PDF#06-0075), [40] and the absence of Pt characteristic signal may be attributed to the low Pt loading amount of 0.9 wt%, corresponding to 0.18 mg cm −2 for loading density on NF, as determined by inductively coupled plasma mass spectrometry (ICP-MS). S7c,d, Supporting Information).…”

Photogenerated Carrier-Assisted Electrocatalysts for Efficient Water Splitting

“…In recent years, multi-field coupling technology has been widely applied in the catalysis field. Introducing some external fields effects can optimize the catalytic process, and the reasonable utilization of resources can also be realized through the interconnection gain between energy fields [28,29]. Electrocatalytic and photocatalytic water splitting are essentially the same, both of which are redox reactions involving an electron transfer process [30].…”