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The development of low-cost, highly active, and rationally designed catalysts is the research trend in electrolytic water reduction. Herein, uniformly dispersed ultra-fine Pt NPs with an average grain diameter of 1.84 nm (DA-Pt (1 : 1)) were effectively loaded onto C3N4 molded and dopamine hydrochloride-modified crinkly nanosheet structures. The plicated structure contributes to the exposure of more surface edge sites, enhancement of metal loading regions, and accessible active sites. The regulation of electronic structure in Pt NPs by O via Pt–O also improves the intrinsic activity of Pt active sites. Additionally, the rich pore structure facilitates mass transfer for HER. As a result, the obtained material is capable of exhibiting effective HER activity in an acidic environment, as well as high-mass activity and long-term stability. DA-Pt (1 : 1) showed comparable current densities to commercial 20 wt% Pt/C (14 and 91 mV) of 10 and 100 mA cm−2 at overpotentials of 17 and 93 mV, respectively. Furthermore, the mass activity of DA-Pt (1 : 1) reached 5526 A gPt−1 at an overpotential of 100 mV, which is four times greater than that of commercial Pt/C (1400 A gPt−1). The research approach presented here is instructive for the development of highly active, low-cost, uniformly dispersed ultrafine Pt NPs. [ABSTRACT FROM AUTHOR]

The high dielectric loss tangent value of black phosphorus nanosheets enables them to be selectively heated under microwave radiation to realize the in situ surface reaction of BP with Ni2+ to prepare thermodynamically unstable two-dimensional Ni2P. [ABSTRACT FROM AUTHOR]

Perovskite-based electrocatalysts with compositional flexibility and tunable electronic structures have emerged as one of the promising non-noble metal candidates for oxygen evolution reaction (OER). Here, we propose a heterostructure comprising perovskite oxide (LaNiO3) nanorods and iron oxide hydroxide (FeOOH) nanosheets as an effective electrochemical catalyst for OER. The optimized 0.25Fe-LNO catalyst with an interesting 1D-2D hierarchical structure shows a low overpotential of 284 mV at 10 mA cm−2 and a small Tafel slope of 69 mV dec−1. The enhanced performance can be explained by the synergistic effect between LaNiO3 and FeOOH, resulting in an improved electrochemically active surface area, facilitated charge transfer and the optimized adsorption of OH intermediates. [ABSTRACT FROM AUTHOR]

Single‐atom catalysts (SACs) on 2D nanomaterials have great potential as efficient and low‐cost electrocatalysts for clean energy technologies. The coordination environments, as well as the physicochemical properties of the 2D supports, play key roles in tuning the catalytic activity and reaction mechanism of the single‐atom centers. This review first summarizes the suitable synthetic strategies of single‐atom on different 2D supports. The methods that facilitate the formation of relative homogeneous structure and enable the regulation of the surrounding atomic environment of metal center are discussed. Furthermore, the recent progress of SACs for energy‐related electrochemical applications is reviewed, including oxygen reduction reaction, hydrogen evolution reaction, oxygen evolution reaction, CO2 reduction reaction, and nitrogen reduction reaction. The strategies about modulation of the electronic structure of single‐atom for enhanced performance are highlighted, together with a discussion of the current issues and the prospects of this field. [ABSTRACT FROM AUTHOR]

Capacitive deionization (CDI) technology shows excellent development prospects in seawater desalination and the removal of heavy metal ions from wastewater due to its high efficiency, environmental protection, and energy saving. However, the lack of suitable electrode materials with excellent performance limits the development of CDI. Herein, a crumpled phosphorus-doped Ti 3 C 2 T x MXene nanosheets (P-Ti 3 C 2 T x) was synthesized by an in-situ phosphating strategy. The P heteroatom doping not only improves the electrical conductivity and modulates the surface properties of Ti 3 C 2 T x MXene nanosheets, but also availably alleviates the self-stacking problem of Ti 3 C 2 T x MXene nanosheets. Specifically, the P-Ti 3 C 2 T x shows excellent multifunctional removal performance for various metal ions (Na+: 61.8 mg g−1, Pb2+: 84.3 mg g−1, and Cr3+: 99.7 mg g−1). Additionally, the removal mechanism of P-Ti 3 C 2 T x is investigated by systematic characterizations and theory calculations. Therefore, this work provides new ideas for the development of multifunctional CDI electrode materials with excellent performance. [Display omitted] • The P-Ti 3 C 2 T x was synthesized by in-situ phosphating strategy. • The P heteroatom doping can modulate the surface properties of Ti 3 C 2 T x MXene nanosheets. • The P-Ti 3 C 2 T x exhibits excellent removal performance for Na+, Pb2+ and Cr3+. • The removal mechanism of P-Ti 3 C 2 T x is explored by various characterizations and DFT calculations. [ABSTRACT FROM AUTHOR]

[Display omitted] Smart hydrogels with good flexibility and biocompatibility have been widely used. The common near-infrared (NIR) photothermal agents are facing a trade-off between good photothermal-conversion efficiency and high biocompatibility. Therefore, developing new metal-free photothermal agents with low cost, high biocompatibility and excellent phase stability is still in urgent need. In this study, we successfully combined poly(N -isopropylacrylamide) (PNIPAM) with the two-dimensional (2D) silicene nanosheets via the in situ polymerization method. Attributed to the thermal-responsive nature of PNIPAM and the excellent photothermal properties of 2D silicene, the obtained silicene/PNIPAM composite hydrogels exhibited dual thermal and NIR responsive properties. This smart hydrogel showed rapid, reversible and repeatable NIR light-responsive behaviors. The volume of this smart hydrogels can shrink significantly under NIR irradiation and recover to its original size without the NIR irradiation. Remote near-infrared light-controlled microfluidic pipelines and electronic switches based on obtained silicene/PNIPAM composite hydrogels were also demonstrated. This work significantly broadens the application prospects of silicene-based hydrogels in remote light-controlled devices. [ABSTRACT FROM AUTHOR]

• The fraction of edges of MoS 2 (WS 2) can be increased by partial etching strategy. • High-yield MoS 2 (WS 2) monolayers were obtained by liquid phase exfoliation. • The semiconducting 2H phase was retained in the MoS 2 (WS 2) monolayers. • Exfoliated MoS 2 (WS 2) monolayers exhibited superior cocatalytic performance. Monolayer MoS 2 (WS 2) nanosheets have triggered tremendous interest due to their fascinating unique properties, but high-yield production of single-layer MoS 2 (WS 2) still remains an enormous challenge and of great interest. Herein, we report a facile efficient partial etching strategy to tailor thickness and lateral size of MoS 2 (WS 2) so as to increase the fraction of edges, which remarkably enhanced the yield of monolayer MoS 2 (20%) and WS 2 (12%) nanosheets by liquid phase exfoliation. As a proof of concept, the exfoliated monolayer MoS 2 (WS 2) nanosheets were applied as the cocatalysts for photocatalytic hydrogen evolution. Notably, the optimized hybrids exhibit excellent hydrogen evolution performance, which are over 31-fold (MoS 2 /CdS) and 47-fold (WS 2 /CdS) higher that of bare CdS counterpart, respectively. Hence, this work not only may pave the new way for the high-yield production of transition-metal dichalcogenides monolayers by liquid phase exfoliation, but also provide the possibility for the further efficiently exfoliating other two-dimension layered materials. [ABSTRACT FROM AUTHOR]

Producing hydrogen through hydrogen evolution reaction by electrolyzing water is a great alternative to solve the energy crisis and air pollution. Earth abundant transition-metal phosphides, especially CoP, have emerged as promising hydrogen evolution reaction catalysts for recent years. Nowadays, attention is focused on combining CoP with other materials to improve its catalytic activity. Herein, in order to get better hydrogen evolution reaction catalyst, we combined CoP nanoparticles with WS 2 nanosheets. Different CoP to WS 2 mass ratios were set to find the best catalytic activity. CoP/WS 2 composites were prepared through a simple ultrasound induced mixing method. And all the CoP/WS 2 composites have enhanced hydrogen evolution reaction catalytic activity than pure CoP nanoparticles and WS 2 nanosheets. Especially, the optimized CoP/WS 2 composite has the lowest onset overpotential of 50 mV, the largest current density of 78 mA/cm 2 at the overpotential of 300 mV, and the smallest Tafel slope of 64.63 mV/decade, indicating excellent hydrogen evolution reaction catalytic activity. [ABSTRACT FROM AUTHOR]

Various large specific surface area carbon-based materials have been considered as fascinating electrode materials for capacitive deionization. However, the low adsorption capacity and sluggish desalination rates of traditional carbon-based materials still impede the further development of capacitive deionization. Herein, we successfully synthesized the nitrogen and fluorine co-doped porous carbon nanosheets (N, F@CNs) with abundant edge-defects via a facile one-pot strategy and systematically investigated its electrochemical properties for capacitive deionization. The introduction of F heteroatom not only effectively improves the edge-defect density and increases the adsorption sites, but also accelerates the ions and electrons transport, which can significantly enhance the electrochemical performance of the N, F@CNs. As a result, in an asymmetric CDI device, the N, F@CNs delivered an excellent salt (Na+) adsorption capacity (71 mg g−1) at the applied potential of 1.2 V, which significantly higher than that of N-doped carbon nanosheets (32 mg g−1), along with outstanding cycling stability. Furthermore, the adsorption/desorption mechanisms involved were detailedly elucidated via systematic characterizations. Therefore, this work provides a new thought for designing carbon-based materials with excellent performance for capacitive deionization. The N, F@CNs exhibits an outstanding salt adsorption capacity, along with outstanding long-term cycling performance. [Display omitted] • The nitrogen and fluorine co-doped porous carbon nanosheets (N, F@CNs) with abundant edge-defects was prepared via a facile one-pot strategy. • The introduction of F heteroatom effectively improved the edge-defect density and increased the adsorption sites. • The N, F@CNs exhibited an outstanding salt (Na+) adsorption capacity. • The desalination mechanisms involved was elucidated by comprehensive characterizations. [ABSTRACT FROM AUTHOR]