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tellwisdom:
Olden days motor. Spits

lemon10:
to play a vital role as a conducting support in providing an effective
electron pathway to the NiOx shell, resulting in an enhanced
OER activity. Following this finding, Liang et al. reported a
NiFeP–amorphous NiFe–OH heterostructure (Fig. 4a), which
was realized by hydrothermal growth of NiFe–OH on Ni foam
and subsequent phosphorization conversion, followed by
electrodeposition of amorphous NiFe–OH on preformed NiFeP
NSs.69 Remarkably, the as-prepared NiFeP/a-NiFe–OH only
required an overpotential of 199 mV at 10 mA cm2 and could
attain 300 mA cm2 at a very low overpotential of 258 mV,
significantly outperforming NiFeP and NiFe LDH pre-catalysts
with similar morphologies and mass loadings (Fig. 4b), which
demonstrated the promotional effect of heterostructuring.
(ii) TMO/TMP heterostructures. Compared to TMPs, TMOs
are usually wide band gap semiconductors or insulators having
much higher electrical resistance. Therefore, unlike TMP/TMO,
improved charge transfer does not prevail in TMO/TMP heterostructures, and the enhanced OER activity usually arises from
the electronic interaction between the TMO and TMP components.
Hao et al. reported the fabrication of NiO@Ni–P core–shell
hybrid NS arrays (Fig. 4c) and found that the hybrid NiO@Ni–P
arrays only required overpotentials of 292 and 350 mV at 10 and
100 mA cm2
, respectively, dramatically lower than those of
NiO and Ni–P NS arrays with similar morphologies and catalyst
loadings (Fig. 4d).70 Their DFT calculations indicated that the
overpotential of the rate-limiting step on the model NiO/Ni–P
interface is smaller than that of NiO or Ni–P, which reasonably
explains the observed better OER activity of the NiO@Ni–P
hybrid, corroborating that coupling of NiO and Ni–P leads to
enhanced OER performance. In addition, a CuO@CoP heterostructured electrode was also recently reported.71 XPS investigations confirmed the electronic interaction between CuO and
CoP, which was used to explain its enhanced OER performance.
However, given that CuO is a photoactive semiconductor,
whether the photoelectrochemical effect comes into play in
the CuO@CoP hybrid remains unclear and deserves further
investigation.
(iii) TMP/TMP heterostructures. TMP/TMP heterostructures
consisting of different TM species in each TMP have been
developed recently aiming to achieve improved OER performance.
For example, Liu et al. reported the fabrication of Ni2P NPs grown
on Fe2P NSs (M-Ni2P/Fe2P–O) using hydrothermal synthesis of
metal hydroxide precursors followed by conventional phosphorization treatment.72 Notably, the M-Ni2P/Fe2P–O showed an extremely low Z10 of 179 mV and a small Tafel slope of 42.7 mV dec1
,
and could sustain at 40 mA cm2 for 120 h without significant
degradation. The researchers attributed the high OER activity to
the synergistic effects of Ni2P/Fe2P interfaces, namely, the active
surface layers and metallic phosphide bulk. The oxidized surface
acted as a proton-coupled electron transfer mediator, expediting
the kinetics of the OER; meanwhile, doped oxyhydroxides could
accelerate the formation of O–O bonds and lower the activation barrier for the OER. Besides, TMP/TMP heterostructures
comprising the same TMP but different polymorphs were also
demonstrated to show a promotional effect on the OER. For
instance, Li et al. recently prepared polycrystalline CoP/CoP2
heterostructures and found that the polycrystalline CoP/CoP2
showed better OER performance than phase-pure CoP because
of the presence of sufficient active sites and Co(II) and Co(IV)
species in the heterostructure.73
(iv) TMP/TMS and TMP/TMX (X = N, C, etc.) heterostructures. In addition to TMP/TMO and TMP/TMP, transition metal
sulfide (TMS), nitride (TMN) and carbide (TMC) were also
reported to composite with TMP for use as heterostructured
pre-catalysts toward the OER. Ni2P–Ni3S2 heterostructures were
reported recently for catalyzing the OER with a small Z10 of
210 mV.74 DFT calculations showed that strong coupling interactions exist between Ni2P and Ni3S2, which result in a lower
H2O adsorption energy value as compared to pure Ni2P or
Ni3S2; meanwhile, the denisty of states (DOS) of Ni2P–Ni3S2 is
in the metallic state with an enhanced carrier density near the
Fermi level with respect to pure Ni2P and Ni3S2, both of which
contribute to the enhanced OER performance.
As far as TMP/TMN heterostructures are concerned, Sun et al.
recently reported the synthesis of Ni2P/CoN hybridized with
N-doped porous carbon polyhedrons (PCP) using a MOF-directed
approach.75 Ni2P NPs were anchored on CoN–PCP by thermal
decomposition of a mixture of NaH2PO2 and NiCl2 in an inert
atmosphere, and the resulting Ni2P/CoN–PCP showed a high
surface area of 712 m2 g1
, which was supposed to result from
the high degree of dispersion of active sites and would promote
mass transport during the eletrocatalytic processes. Besides,
CoP–Mo2C heterostructured pre-catalysts were obtained by a similar
MOF-directed synthesis.76 Notably, the CoP–Mo2C pre-catalyst was
Fig. 4 (a1) SEM and (a2) high-resolution TEM images of NiFeP/a-NiFe–OH
hierarchical nanostructures. (b) iR-corrected polarization curves for the
NiFeP/NiFe–OH recorded at a scan rate of 0.5 mV s1
, along with those
for NiFeP, NiFe–OH, and Ni foam for comparison. (c) TEM image of
NiO@Ni–P NSs. (d) The kinetic-energy barrier profiles of intermediates
and products on NiO, Ni–P, and NiO@Ni–P heterostructures. Inset: Schematic illustration of the NiO@Ni–P interface. Blue, red and pink spheres
represent Ni, O and P atoms, respectively. Panels (a) and (b) reproduced with
permission from ref. 69. Copyright 2017 American Chemical Society. Panels
(c) and (d) reproduced with permission from ref. 70. Copyright 2018
John Wiley & Sons, Inc.
ChemComm Feature Article
Published on 12 June 2019. Downloaded by Nottingham Trent University on 7/18/2019 8:35:29 AM. View Article Online
Chem. Commun. This journal is © The Royal Society of Chemistry 2019
not only active for the OER in alkaline media with an Z10 of 265 mV,
but also capable of catalyzing the OER in 0.5 M H2SO4 showing an
impressive Z10 value of only 330 mV. Moreover, CoP–Mo2C also
exhibited outstanding catalytic stability for the OER in acidic
electrolyte, rendering it one of the best PGM-free acid-stable OER
catalysts reported so far.
(v) TMP/C heterostructures. Compositing catalysts with
carbon has been broadly used as an effective strategy to improve
their catalytic performance. In this respect, numerous works on
TMP/C hybrids have been reported to be used to catalyze the
OER. There are three different types of TMP/C heterostructures,
including (1) TMP NPs supported on carbon-based materials;77
(2) carbon nanostructures, typically nanodots (NDs), supported
on TMPs;78 and (3) TMPs embedded or encapsulated in carbon or
doped-carbon.79 In almost all cases, it is proposed that carbon
makes a positive contribution to the OER performance, by
enabling efficient charge transfer and offering abundant surface
sites for catalyst nucleation by virture of surface chemical affinity
that could have an excellent anchoring effect to prevent the
catalysts from detachment. For example, Liang et al. investigated
the effect of CNTs heterostructured with Co0.7Fe0.3P on the OER
activity, and found that Co0.7Fe0.3P/CNT showed better activity
than unsupported Co0.7Fe0.3P.77 Hou et al. reported Co–Ni–P NSs
embedded with graphene dots (GDs) and demonstrated that the
charge transfer properties were indeed improved after incorporating GDs on Co–Ni–P NSs.80 Even if GDs facilitate charge
transport, the authors found that a high density of GDs dispersed
on Co–Ni–P NSs would lead to a decrease in OER activity. This is
due likely to the increased resistance and the over-occupancy of
GDs on the catalytically active surface. A similar phenonmenon
was also observed in the CoP/C ND composite.78
For TMPs embedded or encapsulated in carbon, although
the positive effect of carbon encapsulation on the enhancement
of the OER has been repetitively reported, it remains unclear
how the OER microscopically takes place on the catalysts. The
prevailing model used to interpret the OER taking place on
transition metal compounds is based on the assumption that
there are exposed metal sites on the surfaces of the catalysts.
While electron conduction may still occur upon carbon encapsulation, how the OH groups or water molecules penetrate the
carbon layer, how and where the O* and *OOH species form,
and how the evolved O2 gas escapes from the intimately
contacted TMP/C interface have not been understood at all.
Wang et al. recently thoroughly investigated the strengthened
synergistic effect (SSE) between MxPy (M = Co, Ni, Cu) and the
carbon layer in an MxPy@C peapod structure on the OER
activity.81 According to their observation, during the OER, MxPy
would be partially oxidized, and the formed oxide served as
catalytically active sites, while the MxPy having tight atomic
contact with carbon would be protected from oxidation, and
thus able to offer fast charge transfer. However, why there was
some MxPy being oxidized and the others not has not been
elucidated.
More importantly, unlike the HER and oxygen reduction
reaction (ORR), the OER proceeds under strong oxidative conditions under which carbon tends to be oxidized,82 forming
carboxylic and phenolic groups and even surface oxides, which
would lead to a degradation. So far, no attention has been paid
to the influence of carbon oxidation on the long-term OER
perforamnce of TMP/C heterostructured pre-catalysts, and investigations in this respect need to be carried out in the future.
Transition metal chalcogenide based
OER pre-catalysts
Transition metal sulfides
Transition metal sulfides (TMSs) have attracted intensive
research attention in electrocatalysis and batteries, due to their
excellent electrical conductivity, tunable metal–sulfur coordination environment and remarkable electronic and chemical
properties.83 For example, under-coordinated Mo–S sites along
the edges of MoS2 possess high chemisorption capability for
hydrogen, thereby being able to lead to high catalytic activity
for the HER.84 Recently, various TMSs have been reported
to catalyze the OER and to directly couple TMS-based HER
catalysts for overall water splitting,11 given that the combination of the same sulfide electrodes will simplify the design
and construction of water electrolyzers and potentially lower
production cost. TMS-based OER pre-catalysts reported so far
primarily include cobalt sulfide, nickel sulfide, iron sulfide,
copper sulfide, molybdenum sulfide, tungsten sulfide and their
composites.5,11 The complex coordination environments between
TM and S render various TM/S stoichiometric compositions.
For example, diverse cobalt sulfide pre-catalysts have been studied
for the OER, including Co3S4, Co9S8, CoS2, and CoS.85,86 These
cobalt sulfide materials can be synthesized by hydrothermal/
solvothermal processing, electrodepo

archieandrews1:
One of Africa biggest artists, Burna Boy just acquired a 2013 ferrari 458 italia from Calidreams automotive in matte gray probably as an early christmas present.

2013?... that boy dyammm chip ilitarate.. . Who drives 2013 in 2019?..ordinary English he can't spek. My ordnary Range rover spot is 2019 & fully loaded!! (Real talk)

tellwisdom:
Poor gurl...U’d better stop thinking everyone here is from ur home.

majamajic:
he is lucky Lagos roads are without potholes now

majamajic:
he is lucky Lagos roads are without potholes now

grandstar:
I lost a lot of respect for him when I discovered he ditched a show without notice.

This is wrong and painful to the organisers.

Denique:
Do you have the "olden days" tyres of the vehicle?

Kingluqman:
I just wan quote you to make the page longer

Yankiss:
6years old car. I know it cost millions sha but why parade an old car? What happened to 2020 model?? our yeyebrities and show off hmmm. How will this news reduce cost of rice for common man??

majamajic:
he is lucky Lagos roads are without potholes now

MrCork:
2013?... that boy dyammm chip ilitarate.. . Who drives 2013 in 2019?..ordinary English he can't spek. My ordnary Range rover spot is 2019 & fully loaded!! (Real talk)

Yankiss:
6years old car. I know it cost millions sha but why parade an old car? What happened to 2020 model?? our yeyebrities and show off hmmm. How will this news reduce cost of rice for common man??

MrCork:
2013?... that boy dyammm chip ilitarate.. . Who drives 2013 in 2019?..ordinary English he can't spek. My ordnary Range rover spot is 2019 & fully loaded!! (Real talk)

Incandescent:
Chief accountant. Well done!

tellwisdom:
Poor gurl...U’d better stop thinking everyone here is from ur home.

majamajic:
he is lucky Lagos roads are without potholes now

majamajic:
he is lucky Lagos roads are without potholes now

AutoReportNG:
Lagos State Governor, Mr Babajide Sanwo-Olu, on Wednesday restated his commitment to collaborate with residents and people of the state for successful implementation of his administration’s policies and programmes.

The governor, who said this when he hosted Muslim faithful in Lagos House, Alausa, Ikeja to mark 2019 Eid-el-Fitri informed the gathering that his government will soon release emergency hotlines to the public to call the Lagos State Public Works for immediate fixing of potholes and roads that need urgent repairs.

“Let us have continuous collaborative engagements. We will continue to ask you to work with us. We would be calling on you at different times.”

“Our Public Works Corporation would come out and start fixing all the potholes on our roads. We would soon publish the numbers that people would be calling to notify us of wherever there are potholes in the state”, Governor Sanwo-Olu stated.

[img]https://1.bp..com/-GbattCohJus/XPgoLH7UhnI/AAAAAAAAcL4/MZwp-uRXcWUWG7rzuHp7bHiRv7iUTQD0wCLcBGAs/s1600/Potholes%2B2.jpg[/img]

He expressed happiness as he joined Muslim brothers and sisters to celebrate the end of Ramadan after a long period of spiritual cleansing and self discipline, urging them to pray for the success of his administration.

According to him, “I am happy and pleased to join our Muslim brothers and sisters in this glorious celebration of Eid-el-fitri. A long stretch of fasting like this is not the easiest thing. It takes special grace and personal discipline, to go through the religious obligation.

“Continue to pray for the success of our administration and our prayers is that we all witness next year in good health and progress”.

[img]https://1.bp..com/-lA51paZZvjo/XPgoZZAmKvI/AAAAAAAAcMA/JwnNS84Rcnkm3PzWuz9qrc4ZUs-VkMqhgCLcBGAs/s1600/Bad-portion.jpg[/img]

Denique:
Do you have the "olden days" tyres of the vehicle?

Denique:
Do you have the "olden days" tyres of the vehicle?

majamajic:
he is lucky Lagos roads are without potholes now

Gistformant:
A Nigerian lawyer 'threw' a party for potholes in front of a bank at Kudirat Abiola Way, Alausa, Ikeja, which he said keeps getting bigger and deeper by the day.

The party for the potholes reached its peak with sodas. The Nigerian lawyer wrote in his tweet addressed to the Lagos State Government and Governor Babajide Sanwo-Olu;


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