Design and Fabrication of Biomass Derived Black Carbon Modified g-C3N4/FeIn2S4 Heterojunction as Highly Efficient Photocatalyst for Wastewater Treatment.

The environmental deterioration caused by dye wastewater discharge has received considerable attention in recent decades. One of the most promising approaches to addressing the aforementioned environmental issue is the development of photocatalysts with high solar energy consumption efficiency for the treatment of dye-contaminated water. In this study, a novel low-cost π-π biomass-derived black carbon modified g-C3N4 coupled FeIn2S4 composite (i.e., FeInS/BC-CN) photocatalyst is successfully designed and fabricated that reveals significantly improved photocatalytic performance for the degradation of Eosin Yellow (EY) dye in aqueous solution. Under dark and subsequent visible light irradiation, the amount optimized composite reveals 99% removal performance for EY dye, almost three-fold compared to that of the pristine FeInS and BC-CN counterparts. Further, it is confirmed by means of the electron spin resonance spectrometry, quenching experiments, and density functional theory (DFT) calculations, that the hydroxyl radicals (•OH) and superoxide radicals (•O2 -) are the dominant oxidation species involved in the degradation process of EY dye. In addition, a systematic photocatalytic degradation route is proposed based on the resultant degradation intermediates detectedduring liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. This work provides an innovative idea for the development of advanced photocatalysts to mitigate water pollution.

Designing State-of-the-Art Gas Sensors: From Fundamentals to Applications.

Gas sensors are crucial in environmental monitoring, industrial safety, and medical diagnostics. Due to the rising demand for precise and reliable gas detection, there is a rising demand for cutting-edge gas sensors that possess exceptional sensitivity, selectivity, and stability. Due to their tunable electrical properties, high-density surface-active sites, and significant surface-to-volume ratio, nanomaterials have been extensively investigated in this regard. The traditional gas sensors utilize homogeneous material for sensing where the adsorbed surface oxygen species play a vital role in their sensing activity. However, their performance for selective gas sensing is still unsatisfactory because the employed high temperature leads to the poor stability. The heterostructures nanomaterials can easily tune sensing performance and their different energy band structures, work functions, charge carrier concentration and polarity, and interfacial band alignments can be precisely designed for high-performance selective gas sensing at low temperature. In this review article, we discuss in detail the fundamentals of semiconductor gas sensing along with their mechanisms. Further, we highlight the existed challenges in semiconductor gas sensing. In addition, we review the recent advancements in semiconductor gas sensor design for applications from different perspective. Finally, the conclusion and future perspectives for improvement of the gas sensing performance are discussed.

Interface Engineering Induced Electron Redistribution at PtNs /NiTe-Ns Interfaces for Promoting pH-Universal and Chloride-Tolerant Hydrogen Evolution Reaction.

Exploring highly efficient hydrogen evolution reaction (HER) electrocatalysts for large-scale water electrolysis in the full potential of hydrogen (pH) range is highly desirable, but it remains a significant challenge. Herein, a simple pathway is proposed to synthesize a hybrid electrocatalyst by decorating small metallic platinum (Pt) nanosheets on a large nickel telluride nanosheet (termed as PtNs /NiTe-Ns). The as-prepared PtNs /NiTe-Ns catalyst only requires overpotentials of 72, 162, and 65 mV to reach a high current density of 200 mA cm-2 in alkaline, neutral and acidic conditions, respectively. Theoretical calculations reveal that the combination of metallic Pt and NiTe-Ns subtly modulates the electronic redistribution at their interface, improves the charge-transfer kinetics, and enhances the performance of Ni active sites. The synergy between the Pt site and activated Ni site near the interface in PtNs /NiTe-Ns promotes the sluggish water-dissociation kinetics and optimizes the subsequent oxyhydrogen/hydrogen intermediates (OH*/H*) adsorption, accelerating the HER process. Additionally, the superhydrophilicity and superaerophobicity of PtNs /NiTe-Ns facilitate the mass transfer process and ensure the rapid desorption of generated bubbles, significantly enhancing overall alkaline water/saline water/seawater electrolysis catalytic activity and stability.

Recent advances in structural engineering of photocatalysts for environmental remediation.

Photocatalysis appears to be an appealing approach for environmental remediation including pollutants degradation in water, air, and/or soil, due to the utilization of renewable and sustainable source of energy, i.e., solar energy. However, their broad applications remain lagging due to the challenges in pollutant degradation efficiency, large-scale catalyst production, and stability. In recent decades, massive efforts have been devoted to advance the photocatalysis technology for improved environmental remediation. In this review, the latest progress in this aspect is overviewed, particularly, the strategies for improved light sensitivity, charge separation, and hybrid approaches. We also emphasize the low efficiency and poor stability issues with the current photocatalytic systems. Finally, we provide future suggestions to further enhance the photocatalyst performance and lower its large-scale production cost. This review aims to provide valuable insights into the fundamental science and technical engineering of photocatalysis in environmental remediation.

The Patient Generated Index (PGI) as an early-warning system for predicting brain health challenges: a prospective cohort study for people living with Human Immunodeficiency Virus (HIV).

PURPOSE: In research people are often asked to fill out questionnaires about their health and functioning and some of the questions refer to serious health concerns. Typically, these concerns are not identified until the statistician analyses the data. An alternative is to use an individualized measure, the Patient Generated Index (PGI) where people are asked to self-nominate areas of concern which can then be dealt with in real-time. This study estimates the extent to which self-nominated areas of concern related to mood, anxiety and cognition predict the presence or occurrence of brain health outcomes such as depression, anxiety, psychological distress, or cognitive impairment among people aging with HIV at study entry and for successive assessments over 27 months. METHODS: The data comes from participants enrolled in the Positive Brain Health Now (+ BHN) cohort (n = 856). We analyzed the self-nominated areas that participants wrote on the PGI and classified them into seven sentiment groups according to the type of sentiment expressed: emotional, interpersonal, anxiety, depressogenic, somatic, cognitive and positive sentiments. Tokenization was used to convert qualitative data into quantifiable tokens. A longitudinal design was used to link these sentiment groups to the presence or emergence of brain health outcomes as assessed using standardized measures of these constructs: the Hospital Anxiety and Depression Scale (HADS), the Mental Health Index (MHI) of the RAND-36, the Communicating Cognitive Concerns Questionnaire (C3Q) and the Brief Cognitive Ability Measure (B-CAM). Logistic regressions were used to estimate the goodness of fit of each model using the c-statistic. RESULTS: Emotional sentiments predicted all of the brain health outcomes at all visits with adjusted odds ratios (OR) ranging from 1.61 to 2.00 and c-statistics > 0.73 (good to excellent prediction). Nominating an anxiety sentiment was specific to predicting anxiety and psychological distress (OR 1.65 & 1.52); nominating a cognitive concern was specific to predicting self-reported cognitive ability (OR 4.78). Positive sentiments were predictive of good cognitive function (OR 0.36) and protective of depressive symptoms (OR 0.55). CONCLUSIONS: This study indicates the value of using this semi-qualitative approach as an early-warning system in predicting brain health outcomes.

Thermo-Chemical Modification of Cellulose for the Adsorptive Removal of Titan Yellow from Wastewater.

This research work focuses on the isolation and thermo-chemical modification of cellulose and its application as an adsorbent for the removal of organic pollutants. The used cellulose was collected from a locally available plant (Olive Europa) commonly called Zaitoon. The stem branches of Zaitoon were collected and then kept in water for 40-45 days at room temperature to extract the cellulose fibers. These cellulose fibers were then kept in the Soxhlet apparatus for washing in n-hexane for 72 h. The purified cellulose was divided into three parts: one part was subjected to thermal activation (TAC), the second was modified chemically (CMC) with Benzyl Chloride, while the last one remained un-functionalized (UFC). All the three forms of cellulose were characterized via FTIR and SEM, then utilized for the removal of Titan Yellow (TY) dye from aqueous media via adsorption process by varying the contact time, temperature, concentration of dye and type, and dose of adsorbent. The adsorption efficiencies of all adsorbents were compared under different experimental variables. Thermally activated cellulose showed the best results for the removal of TY compared with other materials. The calculated removal percentage of TY was found to be 97.69, 94.83, 94.83, and 98% under equilibrium conditions of contact time, temperature, adsorbent dose, and TY concentration. Similarly, the uptake capacities of TAC under optimal experimental conditions were found to be 19.56, 18.96, 18.52, and 18.75 mg/g. Thermodynamic studies of TAC, CMC, and UFC showed that the values of ΔG are negative, while those of ΔH and ΔS are positive in all cases and at all temperatures. This indicates that the TY elimination process is endothermic and spontaneous with an entropy-driven nature. The obtained results indicate that the as-fabricated low-cost biomaterials can effectively remove dyes from wastewater through physicochemical interactions. The removal process was influenced by the nature of the adsorbent and the operating variables.

A Critical Review on Nanowire-Motors: Design, Mechanism and Applications.

Nanowire-motors (NW-Ms) are promoting the rapid development of emerging biomedicine and environmental governance, and are an important branch of micro-nano motors in the development of nanotechnology. In recent years, huge research breakthroughs have been made in these fields in terms of the fascinating microstructure, conversion efficiency and practical applications of NW-Ms. This review article introduces the latest milestones in NW-Ms research, from production methods, driving mechanisms, control methods to targeted drug delivery, sewage detection, sensors and cell capture. The dynamics and physics of micro-nano devices are reviewed, and finally the current challenges and future research directions in this field are discussed. This review further aims to provide certain guidance for the driving of NW-Ms to meet the urgent needs of emerging applications.

A Review on SAPO-34 Zeolite Materials for CO2 Capture and Conversion.

Among several known zeolites, silicoaluminophosphate (SAPO)-34 zeolite exhibits a distinct chemical structure, unique pore size distribution, and chemical, thermal, and ion exchange capabilities, which have recently attracted considerable research attention. Global carbon dioxide (CO2 ) emissions are a serious environmental issue. Current atmospheric CO2 level exceeds 414 parts per million (ppm), which greatly influences humans, fauna, flora, and the ecosystem as a whole. Zeolites play a vital role in CO2 removal, recycling, and utilization. This review summarizes the properties of the SAPO-34 zeolite and its role in CO2 capture and separation from air and natural gas. In addition, due to their high thermal stability and catalytic nature, CO2 conversions into valuable products over single metal, bi-metallic, and tri-metallic catalysts and their oxides supported on SAPO-34 were also summarized. Considering these accomplishments, substantial problems related to SAPO-34 are discussed, and future recommendations are offered in detail to predict how SAPO-34 could be employed for greenhouse gas mitigation.

Green synthesis of SrO bridged LaFeO3/g-C3N4 nanocomposites for CO2 conversion and bisphenol A degradation with new insights into mechanism.

Very recently the green synthesis routes of nanomaterials have attracted massive attention as it overcome the sustainability concerns of conventional synthesis approaches. With this heed, in this novel research work we have synthesized the g-C3N4 nanosheets based nanocomposites by utilizing Eriobotrya japonica as mediator and stabilizer agent. Our designed bio-caped and green g-C3N4 nanosheets based nanocomposites have abundant organic functional groups, activated surface and strong adsorption capability which are very favorable for conversion CO2 into useful products and bisphenol A degradation. Beneficial to further upgrade the performances of g-C3N4 nanosheets, the resulting pristine g-C3N4 nanosheets are coupled with LaFeO3 nanosheets via SrO bridge. Based on our experimental results such as TEM, XRD, DRS, TPD, TGA, PL, PEC and FS spectra linked with OH amount it is confirmed that the biologically mediated green g-C3N4 nanosheets are eco-friendly, highly efficient and stable. Furthermore, the coupling of LaFeO3 nanosheets enlarged the surface area, enhanced the charge separation, while the insertion of SrO bridge worked as facilitator for electron transportation and photo-electron modulation. In contrast to pristine green g-C3N4 nanosheets (GCN), the activities of final resulting sample 6LFOS-(4SrO)-GCN are improved by 8.0 times for CO2 conversion (CH4 = 4.2, CO = 9.2 µmol g-1 h-1) and 2.5-fold for bisphenol A degradation (88%) respectively. More specifically, our current research work will open a new gateway to design cost effective, eco-friendly and biological inspired green nanomaterials for CO2 conversion and organic pollutants degradation which will further support the net zero carbon emission manifesto and the optimization of carbon neutrality level.

Self-Resonant Microlasers of Colloidal Quantum Wells Constructed by Direct Deep Patterning.

Here, the first account of self-resonant fully colloidal µ-lasers made from colloidal quantum well (CQW) solution is reported. A deep patterning technique is developed to fabricate well-defined high aspect-ratio on-chip CQW resonators made of grating waveguides and in-plane reflectors. The fabricated waveguide-coupled laser, enabling tight optical confinement, assures in-plane lasing. CQWs of the patterned layers are closed-packed with sharp edges and residual-free lifted-off surfaces. Additionally, the method is successfully applied to various nanoparticles including colloidal quantum dots and metal nanoparticles. It is observed that the patterning process does not affect the nanocrystals (NCs) immobilized in the attained patterns and the different physical and chemical properties of the NCs remain pristine. Thanks to the deep patterning capability of the proposed method, patterns of NCs with subwavelength lateral feature sizes and micron-scale heights can possibly be fabricated in high aspect ratios.

Photo-Assisted Removal of Rhodamine B and Nile Blue Dyes from Water Using CuO-SiO2 Composite.

Wastewater from the textile industries contaminates the natural water and affects the aquatic environment, soil fertility and biological ecosystem through discharge of different hazardous effluents. Therefore, it is essential to remove such dissolved toxic materials from water by applying more efficient techniques. We performed a comparative study on the removal of rhodamine B (RhB) and Nile blue (NB) from water through a catalytic/photocatalytic approach while using a CuO-SiO2 based nanocomposite. The CuO-SiO2 nanocomposite was synthesized through a sol-gel process using copper nitrate dihydrate and tetraethylorthosilicate as CuO and SiO2 precursors, respectively, with ammonia solution as the precipitating agent. The synthesized nanocomposites were characterized, for their structure, morphology, crystallinity, stability, surface area, pore size and pore volume, by using a scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) techniques. The CuO-SiO2 nanocomposite was used for potential environmental applications in the terms of its catalytic and photocatalytic activities toward the degradation of rhodamine B (RhB) and Nile blue (NB) dyes, in the presence and absence of light, while monitoring the degradation process of dyes by UV-Visible spectroscopy. The catalytic efficiency of the same composite was studied and discussed in terms of changes in the chemical structures of dyes and other experimental conditions, such as the presence and absence of light. Moreover, the composite showed 85% and 90% efficiency towards the removal of rhodamine B and Nile blue dyes respectively. Thus, the CuO-SiO2 nanocomposite showed better efficiency toward removal of Nile blue as compared to rhodamine B dye while keeping other experimental variables constant. This can be attributed to the structure-property relationships and compatibility of a catalyst with the molecular structures of dyes.

Pyropheophorbide-a/(001) TiO2 Nanocomposites with Enhanced Charge Separation and O2 Adsorption for High-Efficiency Visible-Light Degradation of Ametryn.

It is highly desired to enhance charge separation and O2 adsorption of the pyropheophorbide-a (Ppa) to promote visible-light activity and stability. Herein, Ppa modified 001-facet-exposed TiO2 nanosheets (Ppa/001T) nanocomposites with different weight ratios were fabricated via the self-assembly approach by OH induced. Compared with the bare Ppa, the 8% amount optimized 8Ppa/001T sample displayed 41-fold enhanced activity for degradation of Ametryn (AME) under visible-light irradiation. The promoted photoactivities could be attributed to the accelerated charge carrier's separation by coupling TiO2 as thermodynamic platform for accepting the photoelectrons with high energy from Ppa and the promoted O2 adsorption because of the residual fluoride on TiO2. As for this, a distinctive two radicals (•O2- and •OH) involved pathway of AME degradation is carried out, which is different from the radical pathway dominated by •O2- for the bare Ppa. This work is of utmost importance since it gives us detailed information regarding the charge carrier's separation and the impact of the radical pathway that will pave a new approach toward the design of high activity visible-light driven photocatalysts.

Facile Synthesis of ZIF-67 for the Adsorption of Methyl Green from Wastewater: Integrating Molecular Models and Experimental Evidence to Comprehend the Removal Mechanism.

Organic dyes with enduring colors which are malodorous are a significant source of environmental deterioration due to their virulent effects on aquatic life and lethal carcinogenic effects on living organisms. In this study, the adsorption of methyl green (MG), a cationic dye, was achieved by using ZIF-67, which has been deemed an effective adsorbent for the removal of contaminants from wastewater. The characterization of ZIF-67 was done by FTIR, XRD, and SEM analysis. The adsorption mechanism and characteristics were investigated with the help of control batch experiments and theoretical studies. The systematical kinetic studies and isotherms were sanctioned with a pseudo-second-order model and a Langmuir model (R2 = 0.9951), confirming the chemisorption and monolayer interaction process, respectively. The maximum removal capacities of ZIF-67 for MG was 96% at pH = 11 and T = 25 °C. DFT calculations were done to predict the active sites in MG by molecular electrostatic potential (MEP). Furthermore, both Molecular dynamics and Monte Carlo simulations were also used to study the adsorption mechanism.

MXenes as Emerging Materials: Synthesis, Properties, and Applications.

Due to their unique layered microstructure, the presence of various functional groups at the surface, earth abundance, and attractive electrical, optical, and thermal properties, MXenes are considered promising candidates for the solution of energy- and environmental-related problems. It is seen that the energy conversion and storage capacity of MXenes can be enhanced by changing the material dimensions, chemical composition, structure, and surface chemistry. Hence, it is also essential to understand how one can easily improve the structure-property relationship from an applied point of view. In the current review, we reviewed the fabrication, properties, and potential applications of MXenes. In addition, various properties of MXenes such as structural, optical, electrical, thermal, chemical, and mechanical have been discussed. Furthermore, the potential applications of MXenes in the areas of photocatalysis, electrocatalysis, nitrogen fixation, gas sensing, cancer therapy, and supercapacitors have also been outlooked. Based on the reported works, it could easily be observed that the properties and applications of MXenes can be further enhanced by applying various modification and functionalization approaches. This review also emphasizes the recent developments and future perspectives of MXenes-based composite materials, which will greatly help scientists working in the fields of academia and material science.

Synthesis and Micromechanistic Studies of Sensitized Bentonite for Methyl Orange and Rhodamine-B Adsorption from Wastewater: Experimental and DFT-Based Analysis.

This work reports the formation of a novel adsorbent, prepared by activating bentonite with cinnamic acid, which is highly efficient to remove dyes from wastewater. The adsorption efficiency of the cinnamic acid activated bentonite was compared with unmodified bentonite by removing methyl orange and rhodamine-B from polluted water. The characterization was performed through X-ray diffraction (XRD) Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The results indicated that acidic pH and low temperature were more suitable for the selected dyes adsorption. The analysis of the data was done by the Langmuir and Freundlich isotherms; the Freundlich isotherm showed more suitability for the equilibrium data. The data were further analyzed by pseudo-first and pseudo-second-order models to study adsorption kinetics. The results showed that methyl orange and rhodamine-B adsorption obeyed pseudo-order kinetics. The results obtained from this research suggested that acid activation of bentonite with cinnamic acid increased the surface area of the clay and hence enhanced its adsorption efficiency. The maximum adsorption efficiency for the removal of methyl orange and rhodamine-B was up to 99.3 mg g-1 and 44.7 mg g-1, respectively, at 25 °C. This research provides an economical modification technique of bentonite, which makes it cost-effective and a good adsorbent for wastewater treatment.

Near-Field Energy Transfer into Silicon Inversely Proportional to Distance Using Quasi-2D Colloidal Quantum Well Donors.

Silicon is the most prevalent material system for light-harvesting applications; however, its inherent indirect bandgap and consequent weak absorption limits its potential in optoelectronics. This paper proposes to address this limitation by combining the sensitization of silicon with extraordinarily large absorption cross sections of quasi-2D colloidal quantum well nanoplatelets (NPLs) and to demonstrate excitation transfer from these NPLs to bulk silicon. Here, the distance dependency, d, of the resulting Förster resonant energy transfer from the NPL monolayer into a silicon substrate is systematically studied by tuning the thickness of a spacer layer (of Al2 O3 ) in between them (varied from 1 to 50 nm in thickness). A slowly varying distance dependence of d-1 with 25% efficiency at a donor-acceptor distance of 20 nm is observed. These results are corroborated with full electromagnetic solutions, which show that the inverse distance relationship emanates from the delocalized electric field intensity across both the NPL layer and the silicon because of the excitation of strong in-plane dipoles in the NPL monolayer. These findings pave the way for using colloidal NPLs as strong light-harvesting donors in combination with crystalline silicon as an acceptor medium for application in photovoltaic devices and other optoelectronic platforms.

An Overview of the Recent Progress in Polymeric Carbon Nitride Based Photocatalysis.

Recently, polymeric carbon nitride (g-C3 N4 ) as a proficient photo-catalyst has been effectively employed in photocatalysis for energy conversion, storage, and pollutants degradation due to its low cost, robustness, and environmentally friendly nature. The critical review summarized the recent development, fundamentals, nanostructures design, advantages, and challenges of g-C3 N4 (CN), as potential future photoactive material. The review also discusses the latest information on the improvement of CN-based heterojunctions including Type-II, Z-scheme, metal/CN Schottky junctions, noble metal@CN, graphene@CN, carbon nanotubes (CNTs)@CN, metal-organic frameworks (MOFs)/CN, layered double hydroxides (LDH)/CN heterojunctions and CN-based heterostructures for H2 production from H2 O, CO2 conversion and pollutants degradation in detail. The optical absorption, electronic behavior, charge separation and transfer, and bandgap alignment of CN-based heterojunctions are discussed elaborately. The correlations between CN-based heterostructures and photocatalytic activities are described excessively. Besides, the prospects of CN-based heterostructures for energy production, storage, and pollutants degradation are discussed.

Child physical abuse: awareness and practices of medical and dental doctors in Pakistan.

OBJECTIVE: To determine the awareness and practices of doctors and dentists in detecting and reporting suspected cases of child physical abuse. METHODS: The cross-sectional study was conducted from November 2017 to June 2018 at the Hamdard College of Medicine and Dentistry, Karachi, and comprised doctors and dentists practising in public and private hospitals across Pakistan. Data was collected using a predesigned questionnaire to assess knowledge of the social indicators of child physical abuse, response to child physical abuse, and actions taken by the professionals when they believed a child abuse case had been detected. Data was analysed using SPSS 22. RESULTS: Of the 575 healthcare professionals, 371(64.5%) were doctors and 204(35.5%) were dentists; 347(60.3%) were males; 446(77.6%) were working in private hospitals; 384(66.8%) had <10 years of experience; and 99(17.2%) had received formal training of child abuse. While 450(78.3%) subjects strongly agreed on the value of identifying and documenting child physical abuse, 336(58%) did not take any action in suspected cases. CONCLUSIONS: Although doctors and dentists had a positive attitude regarding child physical abuse, the majority preferred to remain silent in suspected cases.

Spatial intensity profiling of elastic and inelastic scattering in isotropic and anisotropic liquids by immersion of a spherical silicon photocell.

The transverse spatial intensity distribution of elastic and inelastic light scattering in passive and active as well as weak and strong scattering liquid media has been studied by using Sphelar One p-n junction silicon spherical photocells. We immersed a Sphelar One in these scattering solutions and measured the photoconductive response in reverse biased photodiode (PD) configuration. The passive weak scattering medium was pure ethanol (EtOH), whereas the passive strong scattering medium was 5CB nematic liquid crystal (NLC). Solutions of 0.1 mM Rhodamine 640 perchlorate laser dye in EtOH and in 5CB NLC were used as active scattering media. The response of Sphelar One was strongly enhanced in 5CB NLC compared to EtOH, as well as in active solutions compared to passive solutions. The morphology of the Sphelar One is already advantageous over conventional one-sided planar PDs inside liquid solutions. This omnidirectional response of the Sphelar One can further be enhanced by optimizing the properties of the surrounding passive elastic and active inelastic scatterers.

Exceptional Visible-Light Activities of TiO2-Coupled N-Doped Porous Perovskite LaFeO3 for 2,4-Dichlorophenol Decomposition and CO2 Conversion.

In this work, TiO2-coupled N-doped porous perovskite-type LaFeO3 nanocomposites as highly efficient, cheap, stable, and visible-light photocatalysts have successfully been prepared via wet chemical processes. It is shown that the amount-optimized nanocomposite exhibits exceptional visible-light photocatalytic activities for 2,4-dichlorophenol (2,4-DCP) degradation by ∼3-time enhancement and for CO2 conversion to fuels by ∼4-time enhancement, compared to the resulting porous LaFeO3 with rather high photoactivity due to its large surface area. It is clearly demonstrated, by means of various experimental data, especially for the ·OH amount evaluation, that the obviously enhanced photoactivities are attributed to the increased specific surface area by introducing pores, to the extended visible-light absorption by doping N to create surface states, and to the promoted charge transfer and separation by coupling TiO2. Moreover, it is confirmed from radical trapping experiments that the photogenerated holes are the predominant oxidants in the photocatalytic degradation of 2,4-DCP. Furthermore, a possible photocatalytic degradation mechanism for 2,4-DCP is proposed mainly based on the resultant crucial intermediate, 2-chlorosuccinic acid with m/z = 153, that readily transform into CO2 and H2O. This work opens up a new feasible route to synthesize visible-light-responsive high-activity perovskite-type nanophotocatalysts for efficient environmental remediation and energy production.