Selective Formation of C2 Products from Electrochemical CO₂ Reduction over Cu_1.8Se Nanowires

Electrochemical reduction of CO2 into higher-value C2 products (e.g., C2H4 and EtOH) is desirable for applications in chemical and fuel industries. Herein, we report that Cu1.8Se nanowires supported on Cu foam can function as an efficient electrocatalyst for selective reduction of CO2 to C2 products, with the Faradaic efficiencies for C2H4 and EtOH production reaching 55% and 24% at −1.1 V, respectively. Additionally, these nanowires also demonstrate a good long-term stability. We believe that the high C2/C1 product selectivity exhibited by the resulting catalyst is more likely due to a high CO2 pressure and the presence of Se species

sj-docx-1-chl-10.1177_17475198211072812 – Supplemental material for A study on the preparation and performance of a graphene-supported, Ce ion-doped, high-efficiency, magnetic TiO2 photocatalyst

Supplemental material, sj-docx-1-chl-10.1177_17475198211072812 for A study on the preparation and performance of a graphene-supported, Ce ion-doped, high-efficiency, magnetic TiO2 photocatalyst by Weiyan Cao, Xijun Liu, Yuwei Wang, Yong Zhang and Congzhi Fu in Journal of Chemical Research</p

Ampere-Level Nitrate Electroreduction to Ammonia over Monodispersed Bi-Doped FeS₂

Electrochemical conversion of NO3– into NH3 (NO3RR) holds an enormous prospect to simultaneously yield valuable NH3 and alleviate NO3– pollution. Herein, we report monodispersed Bi-doped FeS2 (Bi–FeS2) as a highly effective NO3RR catalyst. Atomic coordination characterizations of Bi–FeS2 disclose that the isolated Bi dopant coordinates with its adjacent Fe atom to create the unconventional p–d hybridized Bi–Fe dinuclear sites. Operando spectroscopic measurements combined with theoretical calculations disclose that Bi–Fe dinuclear sites can synergistically enhance the hydrogenation energetics of NO3–-to-NH3 pathway, while suppressing the competitive hydrogen evolution, leading to a high NO3RR selectivity and activity. Consequently, the specially designed flow cell equipped with Bi–FeS2 exhibits a high NH3 yield rate of 83.7 mg h–1 cm–2 with a near-100% NO3–-to-NH3 Faradaic efficiency at an ampere-level current density of 1023.2 mA cm–2, together with an excellent long-term stability for 100 h of electrolysis, ranking almost the highest performance among all reported NO3RR catalysts

High Selectivity Toward C₂H₄ Production over Cu Particles Supported by Butterfly-Wing-Derived Carbon Frameworks

Converting carbon dioxide to useful C2 chemicals in a selective and efficient manner remains a major challenge in renewable and sustainable energy research. Herein, we adopt butterfly wings to assist the preparation of an electrocatalyst containing monodispersed Cu particles supported by nitrogen-doped carbon frameworks for an efficient reduction of CO₂. Benefiting from structure advantages and the synergistic effect between nitrogen dopants and stepped surface-rich Cu particles, the resulting catalyst exhibited a high faradic efficiency of 63.7 ± 1.4% for ethylene production (corresponding to an ethylene/methane products’ ratio of 57.9 ± 5.4) and an excellent durability (∼100% retention after 24 h). This work presents some guidelines for the rational design and accurate modulation of metal heterocatalysts for high selectivity toward ethylene from CO₂ electroreduction

Bifunctional BiPd Alloy Particles Anchored on Carbon Matrix for Reversible Zn–CO₂ Battery

Exploring reversible Zn–CO2 batteries holds great promising potential for future CO2 fixation and energy supply. Herein, the bifunctional PdBi alloy anchoring on carbon substrate (BiPdC) is proposed for simultaneously catalyzing carbon dioxide reduction reaction (CO2RR) and formic acid oxidation (FAO). The synergistic effect between Pd and Bi overcomes the sluggish kinetics of CO2RR and FAO, causing the HCOOH Faraday efficiency (FEHCOOH) of 63.4% and 6.2 mA cm–2 current density for FAO. Benefiting from the CO2–HCOOH interconversion, the homemade reversible Zn–CO2 battery exhibits the optimal 52.6% FEHCOOH and 1.1 V voltage gap within 45 h of cycling

Additional figures from Facile synthesis of Al-doped NiO nanosheet arrays for high-performance supercapacitors

XRD pattern, SEM image and galvanostatic discharge curve

Pd₁Cu Single-Atom Alloys for High-Current-Density and Durable NO-to-NH₃ Electroreduction

Electrochemical reduction of NO to NH3 (NORR) offers a prospective method for efficient NH3 electrosynthesis. Herein, we first design single-atom Pd-alloyed Cu (Pd1Cu) as an efficient and robust NORR catalyst at industrial-level current densities (>0.2 A cm–2). Operando spectroscopic characterizations and theoretical computations unveil that Pd1 strongly electronically couples its adjacent two Cu atoms (Pd1Cu2) to enhance the NO activation while promoting the NO-to-NH3 protonation energetics and suppressing the competitive hydrogen evolution. Consequently, the flow cell assembled with Pd1Cu exhibits an unprecedented NH3 yield rate of 1341.3 μmol h–1 cm–2 and NH3–Faradaic efficiency of 85.5% at an industrial-level current density of 210.3 mA cm–2, together with an excellent long-term durability for 200 h of electrolysis, representing one of the highest NORR performances on record

Hierarchical Zn<i>_x</i>Co_3–<i>x</i>O₄ Nanoarrays with High Activity for Electrocatalytic Oxygen Evolution

The design and fabrication of efficient and inexpensive electrodes for use in the oxygen evolution reaction (OER) is essential for energy-conversion technologies. In this study, high OER performance is achieved using novel hierarchical Zn_<i>x</i>Co_3–<i>x</i>O₄ nanostructures constructed with small secondary nanoneedles grown on primary rhombus-shaped pillar arrays. The nanostructures have large roughness factor, high porosity, and high active-site density. Only a small overpotential of ∼0.32 V is needed for a current density of 10 mA/cm² with a Tafel slope of 51 mV/decade. The nanostructures are also found to perform significantly better than pure Co₃O₄ and a commercial Ir/C catalyst and to perform similarly to the best OER catalysts that have been reported for alkaline media. These merits combined with the satisfactory stability of the nanostructures indicate that they are promising electrodes for water oxidation

Tremella-Like Ni–NiO with O‑Vacancy Heterostructure Nanosheets Grown In Situ on MXenes for Highly Efficient Hydrogen and Oxygen Evolution

Electronic modulation via heterostructures or vacancies has been recently regarded as an effective strategy to improve electrocatalytic activity by optimizing the adsorption free energies of hydrogen evolution reaction (HER) or oxygen evolution reaction (OER) active intermediates during the reaction. Herein, tremella-like Ni–NiO with O-vacancy heterostructure nanosheets grown in situ on Ti3C2Tx MXenes (Ni–NiO/Ti3C2Tx MXene) are fabricated via a facile strategy. Benefitting from the heterointerfaces between Ni and NiO, the synergetic coupling effects of MXenes and Ni–NiO heterostructures, the O-vacancies, and the unique architecture, the as-prepared Ni–NiO/Ti3C2Tx MXene showed superior activity toward the HER and OER in alkaline electrolyte, only requiring overpotentials of 72 mV for the HER and 248 mV for the OER to offer 10 mA cm–2. Density functional theory (DFT) calculations revealed that Ni–NiO with O-vacancies can effectively increase the electron density around the Fermi level and modulate the Gibbs free energies of the intermediates during catalytic reactions, thus accelerating the reaction kinetics

Nanocellulose/Reduced Graphene Oxide Composite Hydrogels for High-Volumetric Performance Symmetric Supercapacitors

When graphene is used as an electrode material for supercapacitors, it tends to have minor volumetric specific capacitance (<200 F cm–3) and low volumetric energy density (<10 Wh L–1) due to its small packing density and poor pseudocapacitive properties. Herein, nanocellulose/reduced graphene oxide composite hydrogels (NCGHs) with a dense porous structure and large packing density are prepared via a simple hydrothermal method using graphene oxide (GO) and nanocellulose (NC) as a reacting substance. In the reaction system, the high-concentration GO solution provides the driving force for the formation of the dense porous structure of NCGHs through the strong π–π stacking interaction between graphene sheets. NC is used as a physical spacer, and its main function is to inhibit the excessive aggregation of NCGHs. Moreover, the super hydrophilicity of NC can also allow it to be used as an electrolyte reservoir to promote the infiltration of NCGHs by the electrolyte. Meanwhile, the oxygen-containing functional groups retained in NCGHs after the hydrothermal reaction can also enhance their wettability and pseudocapacitance. Consequently, the NCGH-40 based binder-less symmetric supercapacitors delivers a high volumetric capacitance (351.8 F cm–3), a large volumetric energy density (12.2 Wh L–1), and a good rate capability of 80.4% even at 10A g–1. Above all, a capacitance augment of 10.4% is achieved after 10,000 cycles at 10 A g–1, confirming its brilliant cycling stability. These parameters suggest that NCGHs can be applied in next-generation energy storage devices with high volumetric energy density