Optimizing Pt-Based Alloy Electrocatalysts for Improved Hydrogen Evolution Performance in Alkaline Electrolytes: A Comprehensive Review

ACS Nano, Journal Year: 2023, Volume and Issue: 17(21), P. 20804 - 20824

Published: Nov. 3, 2023

The splitting of water through electrocatalysis offers a sustainable method for the production hydrogen. In alkaline electrolytes, lack protons forces dissociation to occur before hydrogen evolution reaction (HER). While pure Pt is gold standard electrocatalyst in acidic since 5d orbital nearly fully occupied, when it overlaps with molecular water, generates Pauli repulsion. As result, formation Pt–H* bond an environment difficult, which slows HER and negates benefits using catalyst. To overcome this limitation, can be alloyed transition metals, such as Fe, Co, Ni. This approach has potential not only enhance performance but also increase dispersion decrease its usage, thus overall improving catalyst's cost-effectiveness. excellent adsorption ability metals contributes generation proton-rich local near Pt-based alloy that promotes HER. Significant progress been achieved comprehending mechanism manipulation structure composition electrocatalysts based on alloy. objective review analyze condense latest developments It focuses modified alloys clarifies design principles catalytic catalysts from both experimental theoretical perspective. highlights some difficulties encountered during opportunities increasing performance. Finally, guidance development more efficient provided.

Language: Английский

---

Solvent Engineering of Oxygen‐Enriched Carbon Dots for Efficient Electrochemical Hydrogen Peroxide Production

Small, Journal Year: 2023, Volume and Issue: 19(43)

Published: June 27, 2023

The development of cost-effective and reliable metal-free carbon-based electrocatalysts has gained significant attention for electrochemical hydrogen peroxide (H2 O2 ) generation through a two-electron oxygen reduction reaction. In this study, scalable solvent engineering strategy is employed to fabricate oxygen-doped carbon dots (O-CDs) that exhibit excellent performance as electrocatalysts. By adjusting the ratio ethanol acetone solvents during synthesis, surface electronic structure resulting O-CDs can be systematically tuned. amount edge active CO group was strongly correlated with selectivity activity O-CDs. optimum O-CDs-3 exhibited extraordinary H2 up 96.55% (n = 2.06) at 0.65 V (vs RHE) achieved remarkably low Tafel plot 64.8 mV dec-1 . Furthermore, realistic productivity yield flow cell measured high 111.18 mg h-1 cm-2 duration 10 h. findings highlight potential universal approach enabling electrocatalytic materials improved performance. Further studies will undertaken explore practical implications advancing field electrocatalysis.

Language: Английский

---

Functional Group Modulation in Carbon Quantum Dots for Accelerating Photocatalytic CO₂ Reduction

ACS Applied Materials & Interfaces, Journal Year: 2023, Volume and Issue: 15(28), P. 33868 - 33877

Published: July 7, 2023

This study investigates the mechanism behind enhanced photocatalytic performance of carbon quantum dot (CQD)-induced photocatalysts. Red luminescent CQDs (R-CQDs) were synthesized using a microwave ultrafast synthesis strategy, exhibiting similar optical and structural properties but varying in surface functional group sites. Model photocatalysts by combining R-CQDs with graphitic nitride (CN) facile coupling technique, effects different functionalized on CO2 reduction investigated. technique narrowed band gap R1-CQDs/CN, made conduction potentials more negative, photogenerated electrons holes less likely to recombine. These improvements greatly deoxygenation ability photoinduced carriers, increased light absorption solar energy, raised carrier concentration, resulting excellent stability remarkable CO production. R1-CQDs/CN demonstrated highest activity, production up 77 μmol g–1 within 4 h, which is approximately 5.26 times higher than that pure CN. Our results suggest superior arises from its strong internal electric field high Lewis acidity alkalinity, attributed abundant pyrrolic-N oxygen-containing groups, respectively. findings offer promising strategy for producing efficient sustainable CQD-based address global energy environmental problems.

Language: Английский

---

Graphene Quantum Dot-Mediated Atom-Layer Semiconductor Electrocatalyst for Hydrogen Evolution

Nano-Micro Letters, Journal Year: 2023, Volume and Issue: 15(1)

Published: Sept. 28, 2023

The hydrogen evolution reaction performance of semiconducting 2H-phase molybdenum disulfide (2H-MoS2) presents a significant hurdle in realizing its full potential applications. Here, we utilize theoretical calculations to predict possible functionalized graphene quantum dots (GQDs), which can enhance HER activity bulk MoS2. Subsequently, design GQD-induced in-situ bottom-up strategy fabricate near atom-layer 2H-MoS2 nanosheets mediated with GQDs (ALQD) by modulating the concentration electron withdrawing/donating functional groups. Experimental results reveal that introduction series during synthesis ALQD plays crucial role. Notably, higher and strength electron-withdrawing groups on GQDs, thinner more active resulting are. Remarkably, synthesized ALQD-SO3 demonstrate significantly improved performance. Our provides simple efficient approach for expanding catalytic application Furthermore, it holds substantial developing other transition-metal dichalcogenide materials.

Language: Английский

---

Tailoring the Atomic‐Local Environment of Carbon Nanotube Tips for Selective H₂O₂ Electrosynthesis at High Current Densities

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(46)

Published: Aug. 3, 2023

The atomic-local environment of catalytically active sites plays an important role in tuning the activity carbon-based metal-free electrocatalysts (C-MFECs). However, rational regulation is always impeded by synthetic limitations and insufficient understanding formation mechanism catalytic sites. Herein, possible cleavage carbon nanotubes (CNTs) through crossing points during ball-milling proposed, resulting abundant CNT tips that are more susceptible to be modified heteroatoms, achieving precise modulation atomic at tips. obtained CNTs with N,S-rich (N,S-TCNTs) exhibit a wide potential window 0.59 V along H2 O2 selectivity for over 90.0%. Even using air as source, flow cell system N,S-TCNTs catalyst attains high productivity up 30.37 mol gcat.-1 h-1 @350 mA cm-2 , superior most reported C-MFECs. From practical point view, solid electrolyzer based on further employed realize in-situ continuous generation pure solution (up 4.35 mmol @300 ; 300 h). functionalized hold great promise applications, even beyond generation.

Language: Английский

---

Unveiling Favorable Microenvironment on Porous Doped Carbon Nanosheets for Superior H₂O₂ Electrosynthesis in Neutral Media

Advanced Energy Materials, Journal Year: 2024, Volume and Issue: 14(19)

Published: Feb. 21, 2024

Abstract Designing effective electrocatalysts tailored for targeted reactions requires fundamental insights into the structure dependence of reaction microenvironment. Herein, inspired by finite element simulations, N,O co‐doped carbon nanosheets featuring a hierarchical micro/mesoporous to form an oxygen‐rich and local alkaline‐like microenvironment two‐electron oxygen reduction (2e − ORR) in neutral medium are designed. The situ ex test results confirmed that architecture can elevate pH accelerate generation intermediates (*O 2 , *OOH), leading high‐efficiency H O production. Utilizing this favorable microenvironment, N,O‐CNS 0.5 demonstrated exceptional electrosynthesis performance media, achieving superior yield rate (6705 mmol g catalyst −1 h flow cell). Additionally, comparative experiments density‐functional theory calculations provided confirmation bi‐doping N as active origin responsible electrochemical 2e ORR. This study synergistically manipulates sites, providing opportunity efficient electro‐production medium.

Language: Английский

---

Engineering functionalization and properties of graphene quantum dots (GQDs) with controllable synthesis for energy and display applications

Nanoscale, Journal Year: 2024, Volume and Issue: 16(7), P. 3347 - 3378

Published: Jan. 1, 2024

Graphene quantum dots (GQDs), a new type of 0D nanomaterial, are composed graphene lattice with sp

Language: Английский

---

Enhanced Electron Delocalization Induced by Ferromagnetic Sulfur doped C 3 N 4 Triggers Selective H 2 O 2 Production

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: May 21, 2024

For the 2D metal-free carbon catalysts, atomic coplanar architecture enables a large number of p

Language: Английский

---

Customizing oxygen electrocatalytic microenvironment with S, N codoped carbon nanofibers confining carbon nanocapsules and Co9S8 nanoparticles for rechargeable Zn-air batteries

Applied Catalysis B Environment and Energy, Journal Year: 2024, Volume and Issue: 352, P. 124060 - 124060

Published: April 21, 2024

Language: Английский

---

Advancing H₂O₂ electrosynthesis: enhancing electrochemical systems, unveiling emerging applications, and seizing opportunities

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(16), P. 8137 - 8181

Published: Jan. 1, 2024

Hydrogen peroxide (H

Language: Английский

---