8 research outputs found
Enhanced Overall Water-Splitting Performance: Oleylamine-Functionalized GO/Cu<sub>2</sub>ZnSnS<sub>4</sub> Composite as a Nobel Metal-Free and NonPrecious Electrocatalyst
No full textUsing
emergent highly proficient and inexpensive non-noble metal-based
bifunctional electrocatalysts to overall water splitting reaction
is a pleasingly optional approach to resolve greenhouse gases and
energy anxiety. In this work, oleylamine-functionalized graphene oxide/Cu2ZnSnS4 composite (OAm-GO/CZTS) is prepared and
investigated as a higher bifunctional electrocatalyst for hydrogen
evolution reaction (HER) and oxygen evolution reaction (OER). The
OAm-GO/CZTS shows brilliant electrocatalytic performance and durability
toward H2 and O2 in both acidic and basic media,
with overpotentials of 47 mV for HER and 1.36 V for OER at a current
density of 10 mA cm–2 and Tafel slopes of 64 and
91 mV dec–1, respectively, which are extremely higher
to those of transition metal chalcogenide and as good as of commercial
precious-metal catalysts
Enhanced Hydrogen Evolution Reactions on Nanostructured Cu 2 ZnSnS 4 (CZTS) Electrocatalyst
No full textEnhanced electrocatalytic hydrogen generation from water <i>via</i> cobalt-doped Cu<sub>2</sub>ZnSnS<sub>4</sub> nanoparticles
No full textA novel noble metal-free Co-doped CZTS-based nano-electrocatalyst fabricated by employing a sonochemical method for the enhanced hydrogen evolution reaction (HER) and it shows a superior HER performance and exhibits excellent current stability.</p
CZTS Decorated on Graphene Oxide as an Efficient Electrocatalyst for High-Performance Hydrogen Evolution Reaction
No full textCZTS Decorated on Graphene Oxide as an Efficient Electrocatalyst for High-Performance Hydrogen Evolution Reaction
No full textCu2ZnSnS4 (CZTS) was synthesized by the sonochemical
method using 2-methoxyethanol as the solvent and subsequently decorated
onto graphene oxide (GO synthesized by the modified Hummers’
method) using two different approaches such as in situ growth and
ex situ synthesis followed by deposition. Preliminary characterizations
indicated that the synthesized CZTS belongs to the kesterite structure
with a sphere-like morphology. The in situ-synthesized CZTS/GO (I-CZTS/GO)
composite is used as an efficient electrocatalyst for hydrogen evolution
reaction (HER) which revealed superior electrocatalytic activity with
a reduced overpotential (39.3 mV at 2 mA cm–2),
Tafel slope (70 mV dec–1), a larger exchange current
density of 908 mA cm–2, and charge transfer resistance
(5 Ω), significantly different from pure CZTS. Besides, the
I-CZTS/GO composite exhibits highest HER performance with high current
stability of which shows no noticeable degradation after i–t amperometry. The catalytic activity demonstrates
that the I-CZTS/GO composite could be a promising electrocatalyst
in hydrogen production from their cooperative interactions
Tyramine Functionalized Graphene: Metal-Free Electrochemical Non-Enzymatic Biosensing of Hydrogen Peroxide
No full textHeterostructural CuO–ZnO Nanocomposites: A Highly Selective Chemical and Electrochemical NO<sub>2</sub> Sensor
No full textA simple
one-step chemical
method is employed for the successful synthesis of CuO(50%)–ZnO(50%)
nanocomposites (NCs) and investigation of their gas sensing properties.
The X-ray diffraction studies revealed that these CuO–ZnO NCs
display a hexagonal wurtzite-type crystal structure. The average width
of 50–100 nm and length of 200–600 nm of the NCs were
confirmed by transmission electron microscopic images, and the 1:1
proportion of Cu and Zn composition was confirmed by energy-dispersive
spectra, i.e., CuO(50%)–ZnO(50%) NC studies. The CuO(50%)–ZnO(50%)
NCs exhibit superior gas sensing performance with outstanding selectivity
toward NO2 gas at a working temperature of 200 °C. Moreover, these
NCs were used for the indirect evaluation of NO2 via electrochemical
detection of NO2– (as NO2 converts
into NO2– once it reacts with moisture,
resulting into acid rain, i.e., indirect evaluation of NO2). As compared with other known modified electrodes, CuO(50%)–ZnO(50%)
NCs show an apparent oxidation of NO2– with a larger peak current for a wider linear range of nitrite concentration
from 20 to 100 mM. We thus demonstrate that the as-synthesized CuO(50%)–ZnO(50%)
NCs act as a promising low-cost NO2 sensor and further
confirm their potential toward tunable gas sensors (electrochemical
and solid state) (Scheme 1)
