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In the quest for many sustainable energy conversion technologies such as water splitting and fuel cells, developing inexpensive yet highly efficient and robust electrocatalysts for the oxygen evolution reaction (OER) is urgent but still an enormous challenge. Herein, tip-welded bimetallic iron−cobalt sulfide nanotube arrays with tunable morphology and composition were fabricated via a templatefree method and directly grown on carbon cloth (FeCo 2 S 4 NTA/CC) as a flexible binder-free catalytic electrode. Based on the well-defined hollow nanotube structure, more abundant active sites are exposed, which accelerates the charge transfer process. In addition, the composition of the catalysts also plays an important role in the electrochemical behavior. Benefited from the unique structure and synergistic effect of bimetallic sulfides, the obtained FeCo 2 S 4 NTA/CC exhibits an outstanding electrocatalytic activity toward the OER with an extremely low overpotential of 317 mV to drive a current density of 100 mA cm −2 , a small Tafel slope of 36 mV dec −1 , and excellent durability during the alkaline water electrolysis in 1.0 M KOH.

A novel copper (Cu) and sulfur (S) co‐doped SnO2 material prepared by a facile hydrothermal method is demonstrated as an efficient electrocatalyst for the reduction of CO2 to formate. The as‐prepared SC10 holds rutile structure, whereas both Cu and S are doped well into the SnO2, in which S2− and Cu2+ replace O2− and Sn4+, respectively. The overpotential observed in CO2‐saturated 0.5 M NaHCO3 solution is as low as 130 mV (vs. RHE) at −0.75 V (vs. Ag/AgCl) and the maximum current density also increases to 5.5 mA cm−2 at −1.2 V, which is 7‐times higher than pure SnO2. The catalyst is stable for more than 33 h and the Faradic efficiency of formate is 58.5 %. The as‐synthesized catalyst will open up a novel route for efficient reduction to formate and has a great potential for relieving the greenhouse effect.

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Transition-metal ion doping and efficient decoration by using a co-catalyst have been proven to effectively inhibit the recombination of photogenerated electron-hole pairs and broaden the visible-light response region. Here, we have constructed MoS 2 nanosheets decorated on a copper-doped CdS nanorod composite as a noble-metal-free photoelectrocatalyst. This kind of composite material was constructed through a simple solvothermal method. The morphology, structure, chemical states, photoelectrochemical properties, and other properties were tested by using a diverse range of analytical techniques.Owing to the Cu 2 + doping and the excellent electron-capturing ability of MoS 2 , 5 % MoS 2 /CuÀ CdS (with 7 % Cu 2 + doping in CdS) exhibits excellent hydrogen evolution reaction with a rate of 10.18 mmol h À 1 g À 1 , which is about 48 times higher than that of pure CdS. A significant increase in the photoelectrochemical performance of the composite catalytic material benefits from the synergistic effect between CdS and MoS 2 and fast interfacial charge transfer, owing to the Cu 2 + doping. These findings provide a new thought for further research of the ion doping in photoelectrocatalytic field.