Search

The development of robust and effective photoanodes is crucial for photoelectrochemical hydrogen production via total water splitting. Herein, the Ta 2 O 5 /α-Fe 2 O 3 /Co-Ni PBA (TFPB-1) photoanode was constructed by the compositing n-type Ta 2 O 5 and n-type α-Fe 2 O 3 followed by the deposition of p-type Co-Ni PBA. The IPCE of TFPB-1 was increased to 35.4% compared to 13.9% for Ta 2 O 5 owing to the significantly improved light absorption efficiency, carrier separation efficiency and injection efficiency. The TFPB-1 achieved a current density of 2.78 mA cm -2 at 1.23 V (vs RHE), which was around 18.5 times that of Ta 2 O 5 . The OER overpotential over TFPB-1 was reduced to 0.59 V compared to 1.13 V for Ta 2 O 5 , resulting in a substantial reduction in the free energy of PEC water oxidation over TFPB-1. As a result, TFPB-1 exhibited remarkably enhanced photoelectrocatalytic activity for oxygen evolution through water oxidation.

Recovery of spent Pt/C catalyst is a sustainable low-cost route to promote large-scale application of hydrogen fuel cells. Here, we report a thermal migration strategy to recover the spent Pt/C. In this route, the ZIF-8 is used to produce nitrogen doped porous carbon (NC) with abundant pyrimidine nitrogen sites as the new support. Subsequently, the spent Pt/C, NC, and NH 4 Cl etching reagent are mixed and heated at 900 °C to thermally migrate Pt from Pt/C onto NC with the help of NH 4 Cl etching reagent. The thermal-volatilized Pt tends to be captured by the pyrimidine nitrogen sites of NC support, thus producing the Pt clusters or 4-5 nm Pt particles. The recovered Pt/NC catalyst exhibits the highly stable oxygen reduction activities with a mass activity of 0.6 A mg Pt -1 after 30000-cycle accelerated durability test., (© 2024 Wiley-VCH GmbH.)

Water electrolysis suffers from electron transfer barriers during oxygen evolution reactions, which are spin-related for magnetic materials. Here, the electron transfer at the Fe_{64}Ni_{36}-FeNiO_{x}H_{y} interface is effectively accelerated when the electrode is heated to trigger the Invar effect in Fe_{64}Ni_{36} Invar alloy, providing more unoccupied orbitals as electron transfer channels without pairing energy. As a result of thermally stimulated changes in electronic states, Fe_{64}Ni_{36}/FeNiO_{x}H_{y} achieved a cascaded oxidation of the catalytic center and water. Unlike direct modifications made by varying compositions and synthesis, regulating electronic states by energy field opens a new avenue to discover materials with energy coupling effects.

The preparation of durable and efficient photoanodes for photoelectrochemical water oxidation is of great importance in promoting the development of green hydrogen production and artificial photosynthesis. Here, n-type BiVO 4 was combined with p-type CuI to construct a CuI/BiVO 4 (CIB-1) p-n heterojunction photoanode. The composite photoanode effectively overcame the drawbacks of BiVO 4 , such as low separation and injection efficiency of photogenerated electron-hole pairs. As a result, the CIB-1 had the highest photocurrent density of 1.98 mA cm -2 , which was 2.5 times higher than pure BiVO 4 with 0.79 mA cm -2 at 1.23 V (vs RHE) under AM 1.5G light irradiation. The CIB-1 had a lower Tafel slope of 23.2 mV decade -1 compared to 47.9 mV decade -1 for BiVO 4 , so the water oxidation kinetics was remarkably advanced over CuI/BiVO 4 . Based on DFT calculations, the OER overpotential of 0.480 V for CuI/BiVO 4 was significantly lower than that of 1.546 V for BiVO 4 due to the lower free energy from OH - to oxygen over CuI/BiVO 4 compared to BiVO 4 .

Water electro-oxidation to form H 2 O 2 is an important way to produce H 2 O 2 which is widely applied in industry. However, its mechanism is under debate and HO (ads) , hydroxyl group adsorbed onto the surface of the electrode, is regarded as an important intermediate. Herein, we study the mechanism of water oxidation to H 2 O 2 at Pt electrode using in-situ Raman spectroscopy and differential electrochemical mass spectroscopy and find peroxide bond mainly originated from the coupling of two CO 3 2- via a C 2 O 6 2- intermediate. By quantifying the 18 O isotope in the product, we find that 93% of H 2 O 2 was formed via the CO 3 2- coupling route and 7% of H 2 O 2 is from OH (ads) -CO 3 •- route. The OH (ads) -OH (ads) coupling route has a negligible contribution. The comparison of various electrodes shows that the strong adsorption of CO 3(ads) at the electrode surface is essential. Combining with a commercial cathode catalyst to produce H 2 O 2 during oxygen reduction, we assemble a flow cell in which the cathode and anode simultaneously produce H 2 O 2 . It shows a Faradaic efficiency of 150% of H 2 O 2 at 1 A cm -2 with a cell voltage of 2.3 V., (© 2024. The Author(s).)

Stability is the main challenge for the application of PtCo catalysts because Co tends to leach during the electrochemical reaction. Herein, we immerse and adsorb dopamine to densely coat Pt 0.8 Co 0.2 particles and subsequently thermally carbonize the coating into few-layer nitrogen-doped graphene to produce Pt 0.8 Co 0.2 @NC. This coating effectively hinders direct contact between Pt 0.8 Co 0.2 particles and the electrolyte, thereby enhancing the stability of the catalyst by preventing Ostwald ripening and suppressing competitive adsorption of toxic species, while also bolstering its antipoisoning ability. Experimental results indicate that the thin coating does not compromise the oxygen reduction reaction activity of the catalyst, showcasing a half-wave potential of 0.81 V in alkaline electrolytes. Spectroscopic results suggest that a strong bonding interaction between Pt and the pyridinic N of N-doped graphene contributes to the generation of a dense coating. The coating layer does not affect the four-electron reaction mechanism of the Pt 0.8 Co 0.2 alloy, and the coordinatively unsaturated carbon atoms on Pt 0.8 Co 0.2 @NC serve as active oxygen reduction reaction centers.

A novel ZnO/CuI/Cu foam electrode was constructed, which demonstrated excellent photoelectrocatalytic activity for the self-Fenton degradation of tetracycline in water. The H 2 O 2 yield was 405.0 μmol L -1 over ZnO/CuI/Cu foam (CIZ-3) under light irradiation (100 mW cm -2 ) for 5 h at -1.23 V (vs NHE), which was 1.7 times higher than that of ZnO/Cu foam and 1.6 times higher than that of CuI/Cu foam, respectively. The 99.0% of tetracycline was degraded by CIZ-3 due to its efficient yield of H 2 O 2 to self-catalyzed generation of • OH. The results of the open-circuit potential between CuI and ZnO displayed that the electrons from the conduction band of CuI flowed to ZnO and the holes from the valence band of ZnO migrated to CuI. As a result, the photogenerated electron-hole pairs of ZnO/CuI were efficiently separated, which greatly promoted the photoelectrocatalytic activity of ZnO/CuI/foam. The toxicity of the aqueous tetracycline solution was significantly reduced by observing the growth of Escherichia coli in the treated wastewater.

Targeting selective CO 2 photoreduction into CH 4 remains a challenge due to the sluggish reaction kinetics and poor hydrogenation ability of the unstable intermediate. Here, the active Pt 2+ sites were photodeposited on the SrTiO 3 photocatalyst, which was well demonstrated to manipulate the CH 4 product selectivity. The results showed that SrTiO 3 mainly yielded the CO (6.98 μmol g -1 ) product with poor CH 4 (0.17 μmol g -1 ). With the Pt 2+ modification, 100% CH 4 selectivity could be obtained with an optimized yield rate of 8.07 μmol g -1 . The prominent enhancement resulted from the following roles: (1) the strong electronic interaction between the Pt 2+ cocatalyst and SrTiO 3 could prompt efficient separation of the photoelectron-hole pairs. (2) The Pt 2+ sites were active to capture and activate inert CO 2 into HCO 3- and CO 3 2- species and allowed fast *COOH formation with the lowered reaction barrier. (3) Compared with SrTiO 3 , the formed *CO species could be captured tightly on the Pt 2+ cocatalyst surface for generating the *CH 2 intermediate by the following electron-proton coupling reaction, thus leading to the CH 4 product with 100% selectivity.

Enhancing the charge separation efficiency is a big challenge that limits the energy conversion efficiency of photoelectrochemical (PEC) water splitting. Surface states generated by protonation of TiO 2 are the efficient charge separation passageways to massively accept or transfer the photogenerated electrons. However, a challenge is to avoid the deprotonation of a protonated TiO 2 photoelectrode at the operation temperature. Here, we found that the terminal hydroxyl group (OH T ) as surface states on the TiO 2 surface generated via electrochemical protonation of TiO 2 at 90 °C [90-TiO 2- x -(OH) x ] is thermally stable. As a result, the thermally enhanced photocurrent of the 90-TiO 2- x -(OH) x electrode reached 1.05 mA cm -2 under 80 °C, and the stability was maintained up to 10 h with a slight photocurrent decrease of 3%. The thermally stable surface states as charge separation paths provide an effective method to couple the heat field with the PEC process via thermal-stimulating hopping of polarons.

Advanced photocatalysts are highly desired to activate the photocatalytic CO 2 reduction reaction (CO 2 RR) with low concentration. Herein, the NiSn(OH) 6 with rich surface lattice hydroxyls was synthesized to boost the activity directly under the natural air. Results showed that terminal Ni-OH could serve as donors to feed protons and generate oxygen vacancies (V O ), thus beneficial to convert the activated CO 2 (HCO 3 - ) mainly into CO (5.60 μ mol g -1 ) in the atmosphere. It was flexible and widely applicable for a stable CO 2 RR from high pure to air level free of additionally adding H 2 O reactant, and higher than the traditional gas-liquid-solid (1.58 μ mol g -1 ) and gas-solid (4.07 μ mol g -1 ) reaction system both using high pure CO 2 and plenty of H 2 O. The strong hydrophilia by the rich surface hydroxyls allowed robust H 2 O molecule adsorption and dissociation at V O sites to achieve the Ni-OH regeneration, leading to a stable CO yield (11.61 μ mol g -1 ) with the enriched renewable V O regardless of the poor CO 2 and H 2 O in air. This work opens up new possibilities for the practical application of natural photosynthesis., (© 2024 IOP Publishing Ltd.)

Compressive strain, downshifting the d-band center of transition metal oxides, is an effective way to accelerate the sluggish kinetics of oxygen evolution reaction (OER) for water electrolysis. Here, we find that anisotropic thermal expansion can produce compressive strains of the IrO 6 octahedron in Sr 2 IrO 4 catalyst, thus downshifting its d-band center. Different from the previous strategies to create constant strains in the crystals, the thermal-triggered compressive strains can be real-timely tuned by varying temperature. As a result of the thermal strain accelerating OER kinetics, the Sr 2 IrO 4 exhibits the nonlinear lnj o - T -1 (j o , exchange current density; T, absolute temperature) Arrhenius relationship, resulting from the thermally induced low-barrier electron transfer in the presence of thermal compressive strains. Our results verify that the thermal field can be utilized to manipulate the electronic states of Sr 2 IrO 4 via thermal compressive strains downshifting the d-band center, significantly accelerating the OER kinetics, beyond the traditional thermal diffusion effects., (© 2024. The Author(s).)

The comprehension of activity and selectivity origins of the electrooxidation of organics is a crucial knot for the development of a highly efficient energy conversion system that can produce value-added chemicals on both the anode and cathode. Here, we find that the potential-retaining trivalent nickel in NiOOH (Fermi level, -7.4 eV) is capable of selectively oxidizing various primary alcohols to carboxylic acids through a nucleophilic attack and nonredox electron transfer process. This nonredox trivalent nickel is highly efficient in oxidizing primary alcohols (methanol, ethanol, propanol, butanol, and benzyl alcohol) that are equipped with the appropriate highest occupied molecular orbital (HOMO) levels (-7.1 to -6.5 eV vs vacuum level) and the negative dual local softness values (Δ s k , -0.50 to -0.19) of nucleophilic atoms in nucleophilic hydroxyl functional groups. However, the carboxylic acid products exhibit a deeper HOMO level (<-7.4 eV) or a positive Δ s k , suggesting that they are highly stable and weakly nucleophilic on NiOOH. The combination (HOMO, Δ s k ) is useful in explaining the activity and selectivity origins of electrochemically oxidizing alcohols to carboxylic acid. Our findings are valuable in creating efficient energy conversions to generate value-added chemicals on dual electrodes.

The sluggish electron transfer kinetics in electrode polarization driven oxygen evolution reaction (OER) result in big energy barriers of water electrolysis. Accelerating the electron transfer at the electrolyte/catalytic layer/catalyst bulk interfaces is an efficient way to improve electricity-to-hydrogen efficiency. Herein, the electron transfer at the Sr 3 Fe 2 O 7 @SrFeOOH bulk/catalytic layer interface is accelerated by heating to eliminate charge disproportionation from Fe 4+ to Fe 3+ and Fe 5+ in Sr 3 Fe 2 O 7 , a physical effect to thermally stabilize high-spin Fe 4+ (t 2g 3 e g 1 ), providing available orbitals as electron transfer channels without pairing energy. As a result of thermal-induced changes in electronic states via thermal comproportionation, a sudden increase in OER performances was achieved as heating to completely suppress charge disproportionation, breaking a linear Arrhenius relationship. The strategy of regulating electronic states by thermal field opens a broad avenue to overcome the electron transfer barriers in water splitting., Competing Interests: Competing interests statement:The authors declare no competing interest.

Transition metals are excellent active sites to activate peroxymonosulfate (PMS) for water treatment, but the favorable electronic structures governing  reaction mechanism still remain elusive. Herein, the authors construct typical d-orbital configurations on iron octahedral (Fe Oh ) and tetrahedral (Fe Td ) sites in spinel ZnFe 2 O 4 and FeAl 2 O 4 , respectively. ZnFe 2 O 4 (136.58 min -1 F -1 cm 2 ) presented higher specific activity than FeAl 2 O 4 (97.47 min -1 F -1 cm 2 ) for tetracycline removal by PMS activation. Considering orbital features of charge amount, spin state, and orbital arrangement by magnetic spectroscopic analysis, ZnFe 2 O 4 has a larger bond order to decompose PMS. Using this descriptor, high-spin Fe Oh is assumed to activate PMS mainly to produce nonradical reactive oxygen species (ROS) while high-spin Fe Td prefers to induce radical species. This hypothesis is confirmed by the selective predominant ROS of 1 O 2 on ZnFe 2 O 4 and O 2 •- on FeAl 2 O 4 via quenching experiments. Electrochemical determinations reveal that Fe Oh has superior capability than Fe Td for feasible valence transformation of iron cations and fast interfacial electron transfer. DFT calculations further suggest octahedral d-orbital configuration of ZnFe 2 O 4 is beneficial to enhancing Fe-O covalence for electron exchange. This work attempts to understand the d-orbital configuration-dependent PMS activation to design efficient catalysts., (© 2023 Wiley-VCH GmbH.)

A novel heterojunction photocatalyst of carbonized polymer dots (CPDs)/Bi/β-Bi 2 O 3 is successfully synthesized via a one-pot solvothermal method by adjusting the reaction temperature and time. As a solvent and carbon source, ethylene glycol not only supports the conversion of Bi 3+ to β-Bi 2 O 3 but also undergoes its polymerization, cross-linking, and carbonization to produce CPDs. In addition, partial Bi 3+ is reduced to Bi by ethylene glycol. As a result, the CPDs and Bi are deposited in situ on the surface of β-Bi 2 O 3 microspheres. There are four built-in electric fields in the CPDs/Bi/β-Bi 2 O 3 system, namely, the n-type semiconductor β-Bi 2 O 3 /H 2 O interface, the p-type CPDs/H 2 O interface, the ohmic contact between Bi and β-Bi 2 O 3 , and the Schottky junction between Bi and CPDs. Under the action of four built-in electric fields, the Z-type charge separation mechanism is formed. It promotes the effective separation of the photogenerated electron-hole and greatly improves the yield of H 2 O 2 . Under irradiation for 2 h, the H 2 O 2 production is 1590 μmol g -1 h -1 . The solar energy to H 2 O 2 conversion efficiency is 0.11%.

A thorough comprehension of the mechanism behind organic electrooxidation is crucial for the development of efficient energy conversion technology. Here, we find that trivalent nickel is capable of oxidizing organics through a nucleophilic attack and electron transfer via a nonredox process. This nonredox trivalent nickel exhibits exceptional kinetic efficiency in oxidizing organics that possess the highest occupied molecular orbital energy levels ranging from -7.4 to -6 eV (vs. Vacuum level) and the dual local softness values of nucleophilic atoms in nucleophilic functional groups, such as hydroxyls (methanol, ethanol, benzyl alcohol), carbonyls (formamide, urea, formaldehyde, glucose, and N-acetyl glucosamine), and aminos (benzylamine), ranging from -0.65 to -0.15. The rapid electrooxidation kinetics can be attributed to the isoenergetic channels created by the nucleophilic attack and the nonredox electron transfer via the unoccupied e g orbitals of trivalent nickel (t 2g 6 e g 1 ). Our findings are valuable in identifying kinetically fast organic electrooxidation on nonredox catalysts for efficient energy conversions., (© 2023. The Author(s).)

Photothermal catalysis, which combines light promotion and thermal activation, is a promising approach for converting CO 2 into fuels. However, the development of photothermal catalysts with effective light-to-heat conversion, strong charge transfer ability, and suitable active sites remains a challenge. Herein, the photothermal effect- and interfacial N-Ni/Ta-O bond-modulated heterostructure composed of oxygen vacancy-rich NiO x and Ta 3 N 5 was rationally fabricated for efficient photothermal catalytic CO 2 reduction. Beyond the charge separation capability conferred by the NiO x /Ta 3 N 5 heterojunction, we observed that the N-Ni and Ta-O bonds linking NiO x and Ta 3 N 5 form a spatial charge transfer channel, which enhances the interfacial electron transfer. Additionally, the presence of surface oxygen vacancies in NiO x induced nonradiative relaxation, resulting in a pronounced photothermal effect that locally heated the catalyst and accelerated the reaction kinetically. Leveraging these favorable factors, the NiO x /Ta 3 N 5 hybrids exhibit remarkably elevated activity (≈32.3 μmol·g -1 ·h -1 ) in the conversion of CO 2 to CH 4 with near-unity selectivity, surpassing the performance of bare Ta 3 N 5 by over 14 times. This study unveils the synergistic effect of photothermal and interfacial chemical bonds in the photothermal-photocatalytic heterojunction system, offering a novel approach to enhance the reaction kinetics of various catalysts.

Bismuth vanadate is a promising material for photoelectrochemical water oxidation. However, it suffers from a low quantum efficiency, poor stability, and slow water oxidation kinetics. Here, we developed a novel photoanode of CoS/Mo-BiVO 4 with excellent photoelectrochemical water oxidation performance. It achieved a photocurrent density of 4.5 mA cm -2 at 1.23 V versus the reversible hydrogen electrode, ∼4 times that of BiVO 4 . The CoS/Mo-BiVO 4 photoanode also exhibited good stability, and the photocurrent density generated by the CoS/Mo-BiVO 4 photoanode did not significantly decrease after light irradiation for 2 h. Upon replacement of part of the V with Mo doping in BiVO 4 , the local electric field around the Mo-O bond was enhanced, thus promoting carrier separation in BiVO 4 . The CoS was deposited on the surface of Mo-BiVO 4 , forming a built-in electric field at the interface. Under the action of the bias electric field and the built-in electric field, the carriers of CoS/Mo-BiVO 4 were efficiently separated in the direction of the inverse type II heterojunction. In addition, CoS improved the light absorption and charge injection efficiency of the CoS/Mo-BiVO 4 photoanode.

Strategies to efficiently activate CO 2 by strongly inhibiting the competitive hydrogen evolution reaction process are highly desired for practical applications of the electrochemical CO 2 reduction technique. Here, we assembled a core-shell In@InO x H y architecture on carbon black by one-step reduction of NaBH 4 as a CO 2 -to-formate catalyst with high selectivity. The stable CO 2 -to-formate reaction originates from the creation of steritic frustrated Lewis pairs (FLPs) on the InO x H y shell with In-O Vs (O Vs , oxygen vacancies) Lewis acid, and In-OH Lewis base. During CO 2 reduction, the electrochemically stable FLPs are capable of first capturing and stabilizing protons to protonate FLPs to In-H Lewis acid and In-OH 2 Lewis base due to its strong steric electrostatic field; then, CO 2 is captured and activated by the protonated FLPs to selectively produce formate. Our results demonstrated that FLPs can be created on the surface of oxyphilic single-metal catalysts efficient in accelerating CO 2 reduction with high selectivity.

Freestanding thin films of functional materials enable the tuning of properties via strain and strain gradients, broadening their applications. Here, a systematic approach is proposed to fabricate freestanding CrMnFeCoNi high-entropy alloy (HEA) thin films by pulsed laser deposition using expansion-contraction of NaCl substrates and weak van der Waals interaction of the interface, which form wrinkles with inhomogeneous strain gradients when transferred to a viscous handle. We demonstrate that the nonuniform gradients of external strain ( flexomagnetic effect ) can induce the partial structural phase transition from FCC to BCC in the wrinkled HEA film, resulting in a 10-fold increase in its room-temperature saturation magnetization compared with the unstrained flat HEA film. Furthermore, after applying an external magnetic field, due to the different electron transfer behavior caused by the electron scattering in wrinkled and flat HEA films, their electrocatalytic magnetic responses showed a diametrically opposite picture. Our work provides a promising strategy for tuning physical and chemical properties via complex strained geometries.

The sluggish kinetics of CO 2 activation and reduction severely limit the energy conversion efficiency of electrocatalytic CO 2 reduction into fuels. Here, ZnSn(OH) 6 with an alternating arrangement of Zn(OH) 6 and Sn(OH) 6 octahedral units and SrSn(OH) 6 with an alternating arrangement of SrO 6 and Sn(OH) 6 octahedral units were adopted to check the effects of frustrated Lewis pairs (FLPs) on electrochemical CO 2 reduction. The FLPs were in situ electrochemically reconstructed on ZnSn(OH) 6 by reducing the electrochemically unstable Sn-OH to Sn-oxygen vacancies (Sn-O Vs ) as a Lewis acid site, which are able to create strong interactions with the adjacent electrochemically stable Zn-OH, a Lewis base site. Compared to SrSn(OH) 6 without FLPs, the higher formate selectivity of ZnSn(OH) 6 originates from the strong ability of FLPs to capture protons and activate CO 2 via the electrostatic field of FLPs triggering better electron transfer and strong orbital interactions under negative potentials. Our findings may guide the design of electrocatalysts for CO 2 reduction with high catalytic performances.

The high-grade C 2+ products from CO 2 photoreduction are limited by the kinetic bottleneck. Herein, a multifunctional Au/hydroxide interface was put forward to improve the C-C coupling. As a prototype, the synthesized Au/ZnSn(OH) 6 tuned the CO generation and afforded about 50% electrons toward C 2 H 6 selectivity. The prominent enhancement resulted from the following effects: (1) strong metal-support electronic interactions built an electric field at the interface of ZnSn(OH) 6 nearby the Au nanoparticles, leading to fast transfer of electrons for the C-H and C-C bonding reactions. (2) The surface solid-state Sn-OH and Zn-OH lattice hydroxyls served as donors to feed rich H + and oxygen vacancies (OVs) via hole-induced oxidation for the boosted C 2 H 6 formation. (3) The synergetic OVs and Au sites allowed efficient e - /H + to boost *CO hydrogenation toward *CH 3 and *CH 3 *CH 3 formation into the C 2 H 6 product.

A fabric liner is an ideal self-lubricating material that has been widely used in self-lubricating spherical plain bearings. To investigate the influence of sliding orientation on the tribological properties of fabric liners, samples were prepared for different fiber orientations relative to the sliding direction and wear tests were conducted under normal loads of 25 N to 200 N. Composite-90° (sliding along Kevlar fibers) shows the best friction and wear properties under loads of 50 N and 100 N, while composite-0° (sliding along PTFE fibers) exhibits the best tribological properties when the load increases to 200 N. Due to the formation of a PTFE transfer film, the friction coefficient even decreases during the stable wear stage. Although the dry sliding condition is controlled by a transfer film formed on the friction interface, the contact geometry generated by the interlacing fibers as well as sliding direction continue to dominate the tribological properties under a light load. The combination of a suitable heavy load and sliding along the PTFE fiber is conducive to the formation of a stable and continuous transfer film of debris. Accordingly, the lowest friction coefficient of 0.105 and the lowest wear depth of 0.056 mm are achieved for composite-0° under 200 N., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Electron-hole separation is a main challenge that limits the energy efficiency of photoelectrochemical water splitting for hydrogen fuel production. Surface polaron states with an energy level distribution near the conduction band are highly efficient charge separation passageways to massively accept or transfer the photogenerated electrons. Here, we found that the charge separation via surface polaron states could be further enhanced by heating (<100 °C) to accelerate the electron mobility of surface polaron states. As a result of heating from 30 to 70 °C, the saturated photocurrent increased about 34.5% under 1 sun and 18.3% under 10 suns from heat-induced increase in electron flux of surface polaron states. The heat-sensitive surface-state electron transfer provides a new heat-photoelectricity coupling mechanism to guide the design of new photoanodes that are available for complementary multienergy systems with high energy efficiency.

Substantial overpotentials and insufficient and unstable active sites of oxygen evolution reaction (OER) electrocatalysts limit their efficiency and stability in OER-related energy conversion and storage technologies. Here, a template editing strategy is proposed to graft highly active catalytic species onto highly conductive rigid frameworks to tackle this challenge. As a successful attempt, two types of NiO 6 units of layered Ni BDC (BDC stands for 1,4-benzenedicarboxylic acid) metal organic frameworks are selectively edited by chemical etching-assisted electroxidation to create layered γ-NiOOH with intercalated Ni-O species. In such an interlayer-confined intercalated architecture, the large interlayer space with high ion permeability offers an ideal reaction region to sufficiently expose the OER active sites comprising high-density intercalated Ni-O species, which also suppresses the undesirable γ to β phase transformation, thus exhibiting efficient and durable OER activity. As a result, water oxidation can occur at an extremely low overpotential of 130 mV and affords 1000 h stability at 100 mA cm -2 . The strategy conceptually shows the possibility of achieving stable homogeneous-like catalysis in heterogeneous catalysis., (© 2022 Wiley-VCH GmbH.)

The overpotentials of electrochemical oxygen evolution reaction (OER) inherently originate from high electron transfer barriers of the redox couple driven water oxidation. Here, we propose a heat-induced magnetic transition strategy to reduce the spin-related electron transfer barriers. Coupling heat into electrochemical OER on a ferro-antiferromagnetic core-shell NiFeN@NiFeOOH, the heat-induced ferro-to-paramagnetic transition for NiFeN core at 55 °C and antiferro-to-paramagnetic transition for NiFeOOH shell at 70 °C significantly accelerate and accordingly achieve a cascaded Ni 2+ /Ni 3+ driven water oxidation reaction. In addition, paramagnetic Ni δ+ (δ ≥ 3) in NiFeN@NiFeOOH can thermochemically react with water to produce oxygen. The heat-induced magnetic transition concomitantly triggers the electrochemical redox couple driven water oxidation and the thermochemical water oxidation due to that heat-induced paramagnetic spin reduces the barriers of electricity driving the spin flipping. Our findings offer new insights into constructing the heat-electricity coupling water splitting.

An effective pathway to cope with the sluggish oxygen evolution reaction (OER) is to accelerate the electron transfer kinetics. Transition metal with high valence states doping can accelerate the reaction kinetics to afford high inherent activity. Herein, a novel trimetallic NiFeCr nanoalloy as an OER electrocatalyst is synthesized by replacing partial Fe in the Ni 3 Fe alloy with Cr. In the OER process, Cr leached from the surface layer of the NiFeCr alloy to form a core-shell NiFeCr@NiFeOOH structure. The electrons from the OER intermediates were significantly accelerated by the high-valence Cr 6+ as an electron acceptor at the core-shell interface. As a result, NiFeCr@NiFeOOH exhibited excellent OER performances with a low overpotential of 209 mV at 25 mA cm -2 in 1.0 M KOH on conductive carbon paper, outperforming the Ni 3 Fe alloy without Cr doping. Our work provides a new strategy to design and synthesize the NiFe-based alloy with high OER activity.

With a facile one-pot solvothermal method, an efficient ternary heterojunction photocatalyst carbon quantum dots (CQDs)/Bi/BiOBr is firstly prepared. Ethylene glycol (EG) is used as the solvent and carbon source for the first time. At 190 °C for 3 h, while BiOBr is synthesized, EG is employed to prepare CQDs through bottom-up method. CQDs are grafted by a large number of functional groups with reducibility, which reduce some neighboring BiO + to metal Bi. By modifying the solvothermal temperature and time, CQDs and Bi are in-situ controllably deposited on the surface of BiOBr microspheres. Due to different Fermi levels and work functions, the interfaces of CQDs, BiOBr and Bi are connected through ohmic junctions with low contact impedance. The hot electrons from Bi with surface plasmon resonance (SPR) properties, and electrons in the CB of BiOBr flow to CQDs, forming a C-scheme electron transfer mechanism. O 2 - from CQDs and h + in the VB of BiOBr respectively attack the sites with higher and lower electron density in methyl orange (MO) molecule, resulting in its photodegradation into small molecular products., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Hydrogen production by electrolyzing water is an important technique to store energy from renewables into chemical energy. Many efforts have been made to improve the energy conversion efficiency. In this review article, we mainly summarized the emerging ideas on water oxidation by multi-energy coupling. First, the physicochemical nature of electrolyzing water reaction is described. Then, we conceptually proposed the physical basis of energy coupling with a goal to maximize the energy conversion efficiency and showed the methods to achieve heat-electricity and magnetism-electricity coupling to drive water splitting. Finally, the material requirements for creating efficient energy coupling water splitting system were proposed. These new ideas unlock a big potential direction for developing multi-energy coupling hydrogen production devices to efficiently store the intermittent and fluctuating renewables., Competing Interests: ZH was employed by State Grid Liaoning Electric Power Supply Co. Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The authors declare that this study received funding from Liaoning Electric Power Co., Ltd. The funder had the following involvement in the study: The data collection and analysis., (Copyright © 2022 Han, Yuan, Liu, Zheng, Huang, Yan and Zou.)

Stability and antipoisoning effects are the main challenges for the application of commercial Pt/C catalysts. Herein, we soaked and adsorbed polydopamine to coat Pt particles on commercial Pt/C and subsequently converted the coatings to few-layer N-doped graphene by calcination to produce Pt/C@NC. The coatings effectively block the direct contact of Pt nanoparticles and electrolyte, thus enhancing the catalyst stability by avoiding Ostwald ripening and suppressing the competitive adsorption of toxicants, contributing to the enhancement of the antipoisoning ability. More importantly, the coatings do not hurt the oxygen reduction reaction (ORR) activity of commercial Pt/C, which exhibits a half wave potential of 0.84 V in an acidic electrolyte. The spectroscopic and theoretical results confirmed that the coatings originate from a strong Pt bonding to pyridinic N of N-doped graphene and that the high ORR activity results from the coordinately unsaturated carbon atoms, as the real ORR active sites, to strongly capture electrons from Pt.

Background: Limited and erratic precipitation with inefficient irrigation scheduling often leads to an unstable crop yield and low water-use efficiency (WUE) in semi-arid and semi-humid regions. A 2-year field experiment was conducted to evaluate the effect of three irrigation strategies (conventional irrigation (CK), full-drip irrigation (FI), based on crop evapotranspiration and precipitation forecast, and deficit drip irrigation (DI) (75% FI)) on photosynthetic characteristics, leaf-to-air temperature difference (∆T), grain yield, and the WUE of summer maize., Results: The results showed that the daily average net photosynthetic rate (Pn) of DI and FI increased by 25.4% and 25.8% at jointing stage in 2018, and 26.3% and 26.5% at grain-filling stage in 2019 compared with CK, respectively. At jointing stage in 2018 and grain-filling stage in 2019, the transpiration rate (Tr) of DI was significantly lower than that of FI (P < 0.05) but there was insignificant difference in Pn value (P > 0.05). The ∆T between 12:00-14:00 of DI and FI was significantly lower than that of CK at jointing stage in 2018 and grain-filling stage in 2019 (P < 0.05). The 2-year average grain yields of DI and FI were 11.4 and 11.5 t ha -1 , which increased by 32.4% and 32.8% compared with CK, respectively. The WUE of DI was 2.82 kg m -3 , which was 17.9% and 33.8% higher than that of FI and CK, respectively., Conclusion: Deficit drip irrigation based on crop evapotranspiration and precipitation forecast improves crop WUE and maintains high grain yields in semi-arid and semi-humid regions. © 2021 Society of Chemical Industry., (© 2021 Society of Chemical Industry.)

High barriers of water oxidation mediated by redox couple continuously challenge to maximizing efficiency from renewables to hydrogen energy. Here, an electricity-heat complementary strategy was achieved by a heat-electricity-sensitive interconversion of the α-Ni(OH) 2 /γ-NiOOH redox couple. In our strategy, the thermo-activated effects significantly lower the barrier energies of initial electroxidation of Ni 2+ /Ni 3+ and subsequent chemical water oxidation to the nearly equal value via coupling a low-grade heat field (<100 °C), thereby achieving a consecutive two-step cascade reaction without kinetic delay. As a result, the cascaded water splitting reaction can happen at an extremely low overpotential of 130 mV and affords a low cell voltage of 1.73 V at 100 mA cm -2 at 90 °C in alkaline electrolyte. Our findings open a new avenue to produce hydrogen by complementation and gain effects of different-grade energies.

Mechanistic understanding of the photogenerated charge carrier dynamics in modified semiconductor photoanodes is vital for the efficient enhancement of photoelectrochemical (PEC) water splitting. Here, an in situ femtosecond (fs)-transient absorption spectroscopy (TAS) assisted spectroelectrochemistry technique is used to probe the behavior of charge carriers in rutile TiO 2 nanorod photoanodes under the different applied potentials and different density of surface polaron states that can be tuned via direct electrochemical protonation. We interpreted the background absorption with long-time decay in terms of polaron-mediated ultrafast electron trapping. The depleted surface polaron states on rutile TiO 2 nanorods can trap photogenerated electrons and endow them with a long lifetime; thus, increasing the polaron state density can enhance the charge separation efficiency and the photocurrent density of the TiO 2 nanorod electrode.

Agricultural non-point source pollution has become the main pollution source in China. Ammonia (NH 3 ) volatilization is one of the main factors of agricultural non-point source pollution. Slow-release nitrogen fertilizer (S) has been widely recognized as an efficient management measure to increase crop yields and mitigate NH 3 volatilization. However, few studies have reported the effects of urea (U) blended with slow-release nitrogen fertilizer (UNS) on maize yield and NH 3 volatilization under dryland farming conditions. A two-season field experiment with U, S and various blending ratios of U and S (UNS) under two N application rates (N1: 180 kg N ha -1 , N2: 240 kg N ha -1 ) was conducted to determine their effects on maize yield, NH 3 volatilization and residual soil NO 3 - -N. The results showed that UNS substantially reduced NH 3 volatilization compared with U, primarily because of the relatively low soil pH and electrical conductivity, and the relatively high soil organic matter. UNS significantly increased dry matter, grain yield, N uptake and N use efficiency (NUE), but reduced residual soil NO 3 - -N compared with U and S. Among UNS treatments, the blending ratio of U and S at 3:7 (UNS2) was most effective in improving maize yield and NUE, while mitigating NH 3 volatilization and soil NO 3 - -N leaching. N1 not only reduced N losses, but also increased NUE compared with N2. In conclusion, UNS2N1 is recommended as the best N fertilizer application strategy for the sustainable production of dryland maize in northwest China., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Metal oxides with surface protonation exhibit versatile physical and chemical properties suitable for use in many fields. Here, we develop an electrochemical route to directly protonize the physically assembled oxide particles, such as TiO 2 , Nb 2 O 5 , and WO 3 , in a Na 2 SO 4 neutral electrolyte, which is a result of electrochemically induced oxygen vacancies reacting with water molecules. With no need of electric connection among particles or between particles and conductive substrate, the electrochemical protonation follows a bottom-up particle-by-particle surface protonation mechanism due to the fact that the protonation inducing high surface conductivity creates an efficient electron transfer pathway among particles. Our results show that electrochemical protonation of particles provides a chance to finely functionalize the surface of a single particle by only adjusting electrode potentials. Such a facile, cost-efficient, and green route is easy to run for a large-scale production and unlocks the potential of semiconductor oxides for various applications.

The solid-state redox couple is a vital charge transfer medium for electrochemical water splitting. In this Frontiers article, we summarize the versatile application of redox couples in promoting OER kinetics, in decoupling the HER and OER, and in combined electrochemical-thermochemical water splitting. These new ideas unlock vast potential for applying redox-couple-mediated water splitting to the storage of the intermittent and fluctuating energy derived from renewable sources.

Background: Sustainable greenhouse tomato production requires optimal fertilizer management to achieve the double-win strategy of producing high yields and maximizing profits with less environmental pollution. The objective of this study was to seek an optimal fertilization strategy maintaining high productivity of greenhouse tomato, improving nitrogen use efficiency and reducing nitrate leaching risk., Results: The combined application of soluble organic and chemical fertilizers for topdressing (SOSC) not only produced more fruit yield (75.18 Mg ha -1 ) and plant dry matter (10 449.12 kg ha -1 ), but also enhanced plant nutrients uptake, nitrogen recovery efficiency (39.22%), nitrogen agronomic efficiency (176.78 kg kg -1 ), soluble solids, vitamin C and lycopene content in tomato fruits compared with the other treatments, that is chicken manures for basal application and chemical fertilizer for topdressing (CC), soluble organic fertilizer for topdressing (SO) and soluble chemical fertilizer for topdressing (SC). In terms of soil nutrients residue, SOSC had no obvious NO 3 - -N accumulation area in the 0-60 cm soil layer, unlike large accumulation in the soil layer below 30 cm in SO and SC., Conclusion: The combined application of soluble organic and chemical fertilizers is highly recommended to sustain fruit yield, improve nitrogen use efficiency and reduce soil degradation risks in commercial greenhouse tomato production., (© 2020 Society of Chemical Industry.)

The photoelectrochemical (PEC) water splitting determines by the light absorption and charge extraction/injection. Here, we dispersedly modified the core-shell structured Ni@Ni y Fe 1-y (OH) 2 on Si photoanodes and in-situ electrochemically converted it to Ni@Ni y Fe 1-y OOH to form a Si/SiO x /Ni@Ni y Fe 1-y OOH assembly, exhibiting the adjustable band bending and catalytic ability in water oxidation depending closely on the composition of Ni y Fe 1-y OOH. Combining with the island-like dispersed distribution to maximize the light absorption and the Ni@Ni y Fe 1-y shell as a high work function and a catalytic layer to simultaneously enlarge charge extraction and injection, the Si/SiO x /Ni@Ni 0.7 Fe 0.3 OOH assembly achieved an onset potential of 1.0 V RHE , a saturated current density of 35.4 mA cm -2 and a more than 50 h stability in an electrolyte with pH 9 under AM1.5G simulated sunlight irradiation. Our findings suggested that regulating the charge energetics at Si-electrolyte interface by discontinuously modifying a composition-adjustable core-shell structure is a potential route to develop highly efficient PEC devices., (© 2020 Wiley-VCH GmbH.)

For heterojunction semiconductor photoelectrodes, efficient charge separation is localized in the junction-induced electric field region and charge transfer follows a band-to-band charge-transfer pathway. Here, we found that polaron states at the heterojunction interface have a function of storing and transferring electrons. As a successful demonstration, we verified that the polaron states (Ti 3+ OH) on TiO 2 are not passivated when used to create a CdS/TiO 2 heterojunction and function as an efficient pathway for massively capturing, storing, and transferring the electrons from conduction bands of both TiO 2 and CdS, thus effectively enhancing the charge separation efficiency of the heterojunction photoanode. The electron throughput of polaron states remains a positive correlation with polaron state density. Interfacial electron transfer through the TiO 2 surface polaron states has great potential application in the development of high-performance heterojunction devices based on TiO 2 .

Polaron states on TiO2 photoanodes provide an important electron transfer pathway at the electrode-electrolyte interface. Here, we electrochemically doped single-crystal rutile TiO2 nanorod arrays with exposed (110) facets to produce surface polaron states, Ti3+-OH, which greatly contributed to charge separation and transfer. Our results experimentally clarified the previously confused understanding of the origin of improved photoelectrochemical (PEC) water splitting performance and verified that the enhanced PEC effects mainly arise from surface polaron states instead of grain boundary passivation.

The oxygen evolution reaction (OER) is a vital proton donor for various clean energy technologies. Here, we synthesized IrOx-decorated ultrathin NiFe-LDH nanosheets (thickness 1-2 nm) by a one-step co-precipitation method. The IrOx was uniformly dispersed on the surface of ultrathin NiFe-LDH nanosheets, greatly increasing the active sites and the electric conductivity for NiFe-LDH. As a result, the IrOx/U-NiFe-LDH exhibited excellent OER performance with a low overpotential (236 mV) and a Tafel slope (74.3 mA dec-1).

A challenge in electrochemical CO 2 reduction is inhibiting hydrogen evolution reaction (HER). Herein, a bulk Zn electrode was chosen to reveal the effect of specifically adsorbed Cl - ions on HER during CO 2 reduction. We found that in the Cl - ion-containing electrolyte, the Zn-Cl adlayer formed because the weakly solvated Cl - ions can strip the solvation shell and form a direct chemical bond with the metal Zn. As a result, the Zn-Cl bonds on the Zn electrode notably blocked the hydrogen evolution and significantly facilitated the electron transfer process via the Cl to the vacant orbitals of inert CO 2 , therefore stabilizing the CO 2 - radical and leading to a four times higher CO Faradaic efficiency for CO 2 reduction in the KCl electrolyte than that in the KHCO 3 electrolyte at a moderate potential of -1.2 V versus a reversible hydrogen electrode.

The synthesis of perovskite oxynitrides, which are promising photoanode candidates for solar energy conversion, is normally accomplished by high-temperature ammonolysis of oxides and carbonate precursors, thus making the deposition of their planar films onto conductive substrates challenging. Here, we proposed a facile strategy to prepare a series of perovskite oxynitride films. Taking SrTaO 2 N as a prototype, we prepared SrTaO 2 N films on Ta foils under NH 3 flow by utilizing the vaporized SrCl 2 /SrCO 3 eutectic salt. The SrTaO 2 N films exhibit solar water-splitting photocurrents of 3.0 mA cm -2 at 1.23 V vs. RHE (reversible hydrogen electrode), which increases by 270% compared to the highest photocurrent (1.1 mA cm -2 at 1.23 V vs. RHE) of SrTaO 2 N reported in the literature. This strategy may also be applied to directly prepare a series of perovskite oxynitride films on conductive substrates such as ATaO 2 N (A = Ca, Ba) and ANbO 2 N (A = Sr, Ba)., Competing Interests: The authors declare no competing financial interests., (Copyright © 2019 Tao Fang et al.)

We chemically deposited amorphous Ni(OH)2 layers over TaON particles with irregular surface morphology, and subsequently in situ reduced them to Ni (10-20 nm) nanoparticles, to construct a TaON@Ni photocatalyst. Such a hierarchical hybrid aims to combine the enhanced light absorption by the metal Ni plasmonic effect with accelerated charge separation by a Schottky barrier, and herein, achieves a higher photocatalytic activity in CO2 reduction than TaON.

Tantalum nitride (Ta 3 N 5 ) with an appealing band gap (∼2.1 eV) has emerged as a promising catalyst in the photocatalysis field. However, Ta 3 N 5 application in the photocatalytic hydrogen evolution reaction (HER) is limited due to disadvantages such as unsatisfactory separation and transfer of photogenerated carriers. Here we utilize MoS 2 as co-catalysts to promote the kinetics of photocatalytic H 2 evolution over Ta 3 N 5 . The Ta 3 N 5 nanorods were encapsulated into 3D hydrangea-like MoS 2 for maximizing the contact areas between Ta 3 N 5 and MoS 2 and offering rich active sites. More importantly, spectroscopic analysis and theoretical calculations consistently reveal that the unique interfacial interaction, as well as the matching band alignment between Ta 3 N 5 and MoS 2 , accelerates the photogenerated charge extraction from Ta 3 N 5 to MoS 2 , reducing charge recombination losses in Ta 3 N 5 . Thus, the optimized Ta 3 N 5 /MoS 2 hybrid exhibits a substantially enhanced hydrogen evolution rate (56.5 μmol h -1 ), over 22 times higher than that of pristine Ta 3 N 5 . This work may provide a general strategy to overcome the low photocatalytic activity of nitrides for hydrogen evolution.

Low charge-separation transport efficiency resulting from structural defects largely limits photocatalytic hydrogen production over polymeric graphitic carbon nitride (PCN) photocatalyst. Herein, an electron-donating group, namely p-phenylene, is incorporated into PCN by a polycondensation reaction between carbon nitride and p-phenylenediamine (or p-benzoquinone) to repair the structural defects. The p-phenylene-modified PCN exhibits an almost fivefold increase in H 2 evolution, a threefold increase in photocurrent density, and higher nonradiative rate (0.285 ns -1 ). Spectroscopic studies confirm that p-phenylene tends to bridge the heptazine-based oligomers through a polycondensation reaction. Theoretical calculations reveal that anchoring of the heptazine units by p-phenylene induces localization of h + and e - on the phenylene and melem moieties, respectively, which effectively separates the charge carriers. This strategy provides an opportunity to overcome structural defects in carbon nitride for efficient photocatalytic solar energy conversion., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Perovskites have been firmly established as one of the most promising materials for third-generation solar cells. There remain several great and lingering challenges to be addressed regarding device efficiency and stability. The photovoltaic efficiency of perovskite solar cells (PSCs) depends drastically on the charge-carrier dynamics. This complex process includes charge-carrier generation, extraction, transport and collection, each of which needs to be modulated in a favorable manner to achieve high performance. Two-dimensional materials (TDMs) including graphene and its derivatives, transition metal dichalcogenides (e.g., MoS2, WS2), black phosphorus (BP), metal nanosheets and two-dimensional (2D) perovskite active layers have attracted much attention for application in perovskite solar cells due to their high carrier mobility and tunable work function properties which greatly impact the charge carrier dynamics of PSCs. To date, significant advances have been achieved in the field of TDM-based PSCs. In this review, the recent progress in the development and application of TDMs (i.e., graphene, graphdiyne, transition metal dichalcogenides, BP, and others) as electrodes, hole transporting layers, electron transporting layers and buffer layers in PSCs is detailed. 2D perovskites as active absorber materials in PSCs are also summarized. The effect of TDMs and 2D perovskites on the charge carrier dynamics of PSCs is discussed to provide a comprehensive understanding of their optoelectronic processes. The challenges facing the PSC devices are emphasized with corresponding solutions to these problems provided with the overall goal of improving the efficiency and stability of photovoltaic devices.

The hydrogen evolution reaction (HER) in alkaline electrolytes is restricted severely by sluggish water dissociation in the Volmer step. Here, we embedded Co crystals into a N-doped carbon (Co@NC) on nickel foam (NF) framework and electrochemically oxidized them in situ to construct a CoO x H y [a mixture of Co(OH) 2 and CoOOH] antenna-modified Co@NC core-shell assembly (NF/Co@NC/CoO x H y ). The CoO x H y antennas significantly decreased the activation energy of water dissociation to protons (the Volmer step), and hydrogen production over the Co core activated NC shell may follow a multi-carbon catalytic mechanism activated by Co and N atoms. As a result, the NF/Co@NC/CoO x H y configuration exhibits a 40 mV onset potential, a low HER overpotential of 51 mV at 10 mA cm -2 , and a current density still reaching around 20 mA cm -2 after 55 h of stability testing in alkaline electrolyte. Our material functionalization strategy may open up a new approach for developing water-alkali electrolysers for use in efficient renewable energy conversion.

Quantitative knowledge of the spatial variability of soil infiltration processes caused by canopy rainfall redistribution has significant hydro-chemical consequences owing to their influence on nutrients leaching and groundwater recharge in agricultural ecosystems. The heterogeneity of throughfall and stemflow under the maize canopy was quantified in this study, and its subsequent effect on soil water distribution at the row scale was further examined. Throughfall at 15 locations within and between maize rows as well as stemflow was observed over three growing seasons of 2015, 2016 and 2017 on the Loess Plateau of China. Soil water content at five depths in the row and interrow positions were continuously monitored. The results showed that throughfall was significantly different among the five sampling sections between maize rows, with the highest throughfall in the center and a decreasing trend towards the maize row. Greater throughfall was observed on the windward side of the maize row than on the leeward side. These spatial patterns persisted for most rainfall events. However, much higher net rainfall (throughfall plus stemflow) was obtained in the row positions when stemflow was further considered. Net rainfall reaching the row positions resulted not only in earlier water infiltration, but also in deeper penetration. The results suggested that the presence of maize canopy altered the soil surface water flux and thus caused heterogeneous infiltration water in the soil, which has implications for guiding the placing of fertilizers/pesticides and soil erosion management in the maize field., (Copyright © 2019 Elsevier B.V. All rights reserved.)