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Reliable and sustainable energy storage systems are crucial for a renewable energy future. The ultrahigh theoretical specific capacity and energy density of lithium–sulfur batteries (LSBs) make them one of the most promising next-generation battery technologies. However, their large-scale applications are seriously limited by rapid capacity fading and poor Coulombic efficiency owing to the shuttling of lithium polysulfides (LiPSs). Herein, we investigate nickel phosphide (Ni 2 P) as an effective host material to realize high-performance LSBs based on first-principles density functional theory (DFT) calculations. Our calculated adsorption energies of the LiPSs species reveal that the Ni 2 P(0001) surface possesses moderate to high adsorption strength and the adsorption process is facilitated via charge transfer from the LiPSs to the interacting Ni 2 P(0001) surface atoms. Due to the strong interactions between Ni 2 P(0001) and LiPSs (Li 2 S x , x = 1, 2, 4, 6 and 8), we observe elongation of the intramolecular Li–S bonds in LiPSs upon their adsorption. The stronger adsorption of Li 2 S coupled with its spontaneous dissociation suggests a faster charging process could occur on the on Ni 2 P(0001) surface. These results demonstrate that Ni 2 P can provide effective anchoring sites for the soluble LiPSs, potentially having implications for the design of electrodes for practical LSBs. [Display omitted] • Accurate first-principles characterization of LiPSs adsorption geometries. • Description of active sites on Ni 2 P (0001) surface. • Elucidation of charge transfer dynamics and anchoring behavior. • Findings on LiPSs catalytic degradation mechanisms and redox kinetics. [ABSTRACT FROM AUTHOR]

Ni 2 P nanosheets were fabricated on carbon fiber using the hydrothermal method and subsequent phosphatization process. The highly conductive Ni 2 P nanosheet arrays could not only facilitate electron transport but also shorten the ion diffusion path. The in-situ grown Ni 2 P nanosheet arrays could be applied as the cathode in Zn battery without any additives and binder. The Ni 2 P//Zn battery based on Ni 2 P nanosheet arrays and metal Zn electrode exhibits excellent electrochemical performance, such as high operating voltage (1.78 V), specific capacity of 231 mAh g−1, and energy density of 318 Wh Kg−1. In addition, the Ni 2 P//Zn battery can maintain a specific capacity retention ~ 80% after 1500 continuous cycles. In view of the excellent electrochemical properties of Ni 2 P//Zn battery, the Ni 2 P will be a potential material for next-generation energy storage devices. • Ni 2 P nanosheet arrays are synthesized on carbon fiber by a two-step procedure. • The Ni 2 P electrode exhibits high specific capacity and good cyclic performance. • A novel Ni 2 P//Zn battery with Zn on carbon fiber as anode was assembled successfully. • The battery with high operating potential shows an energy density of 318 Wh kg−1. [ABSTRACT FROM AUTHOR]

Inorganic-organic hybrid materials, a class of probable candidates for combining two counterparts into one structure could be beneficial for improving or combing the excellent electronic, magnetic, rigidity and thermal stability, and optical feathers of inorganic frameworks with diverse structure, processability, flexibility and good geometric controllability of organic molecules. Anchoring inorganic-organic hybrid materials with cocatalysts is a usually used strategy for enhancing their catalytic performance. However, noble metal cocatalysts always limit their practical application. Herein, we report that noble metal free cocatalyst of Ni 2 P decorated CdS-diethylenetriamine (CdS-DETA) can effectively overcome this limitation to achieve highly photocatalytic hydrogen production. The rapid microwave solvothermal synthesis of CdS-DETA (MCdS-DETA) process shortens reaction time, saves energy and lead to achieve highly photocatalytic activity due to its low crystallinity. When Ni 2 P decorated MCdS-DETA, The 0.4%Ni 2 P/MCdS-DETA exhibited the highest photocatalytic hydrogen evolution activity (6836 μmmol h−1 g−1), which is 4.14 times, 2.06 times and 1.34 times higher than traditional solvothermal CdS-DETA(TCdS-DETA), MCdS-DETA and Pt cocatalysted MCdS-DETA, respectively. The method reported here can be extended to other inorganic-organic hybrid materials, and develops new strategies for exploring inorganic-organic hybrid-based photocatalysts. Unlabelled Image • Novel Ni 2 P/CdS-ETDA composites were obtained. • The composites exhibited excellent photocatalytic hydrogen production. • Ni 2 P is a superior cocatalyst for photocatalytic hydrogen production. • Ni 2 P/CdS-ETDA is stable during the photocataytic reaction. [ABSTRACT FROM AUTHOR]

Abstract: Al2O3-SiO2-based Co(Ni)-Mo(W)-S catalysts are widely investigated hydrodesulfurization (HDS) catalysts in recent decades. XPS is a suitable technique to detect the surface properties of HDS catalysts. Typical overlapping spectra in the XPS analysis of HDS catalysts, such as Mo3d and S2s, Si2p and bremsstrahlung-induced Al KL23L23 using nonmonochromatic AlKα source, W4f and W5p3/2, as well as the disturbance of Auger lines on Ni2p and Co2p, are carefully studied in the present paper. Besides, effective methods to overcome the influence of peak overlaps are illustrated. These results would provide basic and important information in interpreting XPS results of HDS catalysts. [Copyright &y& Elsevier]

Modification of cauliflower-like Mn 0.2 Cd 0.8 S with Ni 2 P can accelerate charge separation and provide abundant active sites, which displayed an enhanced photocatalytic H 2 evolution activity under visible light irradiation. [Display omitted] • The composite was prepared by a facile solvothermal method. • Contact interface between Ni 2 P and Mn 0.2 Cd 0.8 S was achieved. • Loading Ni 2 P can provide abundant active sites. • The heterojunction can promote charge carriers separation. • The composite exhibited an enhanced photocatalytic H 2 evolution activity. Modification with co-catalyst has been regarded as an effective strategy to improve the photocatalytic H 2 evolution activity of Mn x Cd 1−x S. Herein, cauliflower-like Mn x Cd 1−x S decorated with Ni 2 P nanoparticles has been prepared via solvothermal method. Experiment results confirmed that modification with Ni 2 P could promote charge transfer efficiency and boost surface reaction rate of Mn x Cd 1−x S. The superior activity of 14.20 mmol g−1h−1 was obtained over the 3 wt% Ni 2 P/Mn 0.2 Cd 0.8 S composite, which was approximately an 8.3-fold enhancement over pure Mn 0.2 Cd 0.8 S. Furthermore, the activity over Mn 0.2 Cd 0.8 S modified with Ni 2 P was higher than other Ni-based co-catalysts (Ni, Ni 2 S, Ni(OH) 2 , NiB and NiSe 2) modification. This work offers a new perspective to design highly efficient photocatalytic system towards H 2 evolution. [ABSTRACT FROM AUTHOR]

• A novel C 3 N 4 nanotube/NCDs/Ni 2 P composite photocatalyst was prepared by decorating N-doped carbon dots (NCDs) and Ni 2 P nanoparticles on C 3 N 4. • The CNT/NCDs/Ni 2 P composite achieves hydrogen production rate of 627.2 µmol g-1h−1 which is well above that of CNT/NCDs and CNT/Ni 2 P, respectively (no detection and 48.5 μmol g-1h−1). • The heterojunction promoted charge carriers separation because of the double Z-scheme charge transfer mechanism. • The C 3 N 4 nanotube/NCDs/Ni 2 P composites are relatively stable even after five consecutive repetitive cycles with remarkable enhanced H 2 production activity. Photocatalyst with double Z-scheme mechanism can promote the separation and transmission of photo-induced carriers effectively. In this work, a novel C 3 N 4 nanotube (CNT)/N-doped carbon dots (NCDs)/Ni 2 P composite photocatalyst was prepared by decorating NCDs and Ni 2 P nanoparticles on CNT, respectively. A variety of test results, including photoluminescence spectra (PL), electrochemical impedance spectrum (EIS) and transient photocurrent responses (TPR), show that compared with CNT and CNT/Ni 2 P, CNT/NCDs/Ni 2 P composite can dramatically facilitate the separation and transmission of charge. Impressively, the CNT/NCDs/Ni 2 P composite achieves a hydrogen evolution rate of 627.2 µmol g-1h−1 which is well above that of CNT and CNT/Ni 2 P, respectively (no detection and 48.5 μmol g-1h−1). Combining the above characterization results with energy band calculation, we speculate that the remarkably optimized photocatalytic activity was predominantly ascribed to the double Z-scheme charge transfer mechanism for CNT/NCDs/Ni 2 P nanocomposite. This work provides a new member for family of photocatalysts with double Z-scheme mechanism, which is beneficial to further fundamental and applied research. [ABSTRACT FROM AUTHOR]

• Heterostructure of Ru 2 P particles decorated Ni 2 P nanosheets is prepared. • Synergism induces accelerated kinetics and intrinsic activity. • Improved active sites density and enhanced charge transfer are obtained. • Showing robust activity and stability for HER in wide pH range. Lacking efficient and pH-universal catalysts is currently the main obstacle for the large-scale production of hydrogen through electrochemical water splitting. The hetero material of Ru 2 P nanoparticles and Ni 2 P nanosheets is constructed on carbon fiber cloth as pH-tolerant catalyst for hydrogen generation. The designed heterointerface provides synergism and structure advantages for improved intrinsic catalysis activity, more accessible active sites, and enhanced charge transfer for hydrogen evolution. The electrochemical measurements demonstrate the active hydrogen production properties, such as low overpotentials (46 mV, 47 mV, and 51 mV in 0.5 M H 2 SO 4 , 1 M KOH, and 1 M phosphate-buffered saline, respectively) at a current density of 10 mA cm−2, as well as rapid catalysis kinetics with small Tafel slopes and good stability. [ABSTRACT FROM AUTHOR]

The development of high catalytic activity, earth-abundant, low-cost, and long-term stability electrocatalysts is highly desirable. In this study, oxygen surface treated Ni 2 P nanosheets as bifunctional catalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is proposed based on density functional theory calculations. The mechanism of the enhanced electrocatalytic performance was investigated by considering oxygen adsorption and substitution of surface phosphorus on the Ni 2 P nanosheets surface. The results show that six O adsorption and six O substitution Ni 2 P exhibit excellent electrocatalytic performance because of their tuned Gibbs free energy and overpotential for hydrogen/oxygen evolution reaction being just −0.21 eV/0.27 V and − 0.15 eV/0.45 V, respectively. Additionally, due to the reducing of total potential, the catalysts can present better OER performance in alkaline media. The bicatalytic activities of O adsorption and O substitution can be well-explained by an amendatory p band-center model, which is also suitable for a broad class of surface engineering systems. This theoretical study not only provides vital insights into the enhanced mechanism of the bifunctional activities of water splitting but also helps to prescribe the principles for designing high performance multifunctional electrocatalysts. Unlabelled Image • Oxygen surface treated Ni 2 P for HER and OER were investigated by DFT calculation • Both O adsorption and O substitution Ni 2 P exhibit excellent electrocatalytic performance • The activities of Oxygen surface treated Ni 2 P can be well explained by an amendatory p band-center model. [ABSTRACT FROM AUTHOR]